biology science unit-2 - nims · pdf fileresult of phyto-hormones. plants respond to stimuli...

BiologyUnit - 2

Content and coordination

SCIENCE UNIT-2 BIOLOGY139

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Syllabus Coverage

Unit 2 - Content and coordination

Biology

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Organisms respond to changes in the environment

Coordination in plants

Plant movements (tropic and nastic movements)

Demonstration of responses of plant parts to various stimuli

Plant Hormones (Phytohormones)

Coordination in animals

Nervous system in animals

Reflex actions, involuntary and voluntary actions

Human Nervous system

Chemical coordination in animals

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Photoperiodism

Human brain and its functions

Role of cholinesterase insecticides and "nerve gas"

Brain diseases and EEG as an important tool

Sense organs and their functions

Diseases of the endocrine system

EXTENSION

SCIENCE UNIT-2BIOLOGY

UNIT 2: Content and Coordination

Learning outcomes - Foundation

In the earlier lessons, students have studied that the body of all living organisms is made up of cells. These cells aggregate and differentiate to form tissues and assembly of different tissues forms different organs. The various organs perform their functions at the right time so that they can work together efficiently. Therefore, some form of control is needed to coordinate their functions. For example, when we eat food, our eyes help in locating the food, our nose senses the food, our hand brings the food to our mouth and our jaw muscles help the teeth to chew the food.All these activities occur in a coordinated manner, and if any of these activities misses or does not occur in time then the body will not get nutrition.

In case of animals, including man, the chemicals produced by ductless (endocrine) glands also bring about coordination. This coordination by chemicals is brought about by the endocrine system. On the other hand the nervous system consists of a series of nerve cells throughout the body. Signals from one part of the body are transmitted to another part through these nerve cells.

At the end of this unit, students should be able to :

Recognize the need for control and co-ordination in the body of various organisms

Describe the methods of co-ordination in plants and animals.

Learn about various types of movements that occur in plants

List various plant hormones and discuss about their functions

Relate nervous system and endocrine system with the function of control and coordination

Recognise sense organs as gateways for receiving information from the environment

Recall nerve cell as the basic structural and functional unit of nervous system and explain the terms synapse and nerve

Define nerve impulse

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SCOPE DOCUMENT

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Identify the components of central nervous system and explain what is grey matter and white matter

Describe the location and structure of spinal cord and recognise its function relating to reflex action

Draw an outline diagram of human body and show the location of various endocrine glands

List the hormones secreted by pituitary, thyroid and pancreas

Give a brief idea of feedback mechanism in hormonal activity

At the end of this unit, students should be able to :

Describe the major regions of human brain and list their functions

Summarize the direct actions of the brain and spinal cord on controlling:

odetection of environmental change

consciousness

learning and memory

emotions

movement

Summarize what we know about cholinesterase insecticides and "nerve gas"

Brain diseases can turn out be devastating

Brain waves can be detected by the technique called EEG

Name the parts of the eye and explain vision in simple terms

Explain accommodation of the eye and give reasons for short sightedness (myopia), long sightedness (hypermetropia) and their correction

Explain the structure and working of the ear

Describe various ways of taking care of sense organs;

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Learning outcomes - Extension

SCIENCE UNIT-2BIOLOGY142

State the symptoms and cause of cretinism, goitre and diabetes mellitus

Vocabulary builds up

Story writing on how different areas in brain coordinate with each other

Prepare model and cut outs of Brain and different endocrine glands.

Jig saw of brain

Case studies and data analysis

Powerpoints

Animations

Discovery of Hormones.

Occurrence of disorders in various geographical areas

Song on Hormones

Ductless glands that are within

They are called the endocrine

Make chemicals that flow within;

And work with the nervous system

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Cross Curricular Links

English:

Arts:

Maths:

ICT:

History:

Geography:

Music:


Hormones, hormones

Chemical messengers are what you call the hormones

Each gland produces one or more hormones

With names that end with “...ins" and "...ones"

Cortisone, testosterone are just two of the hormones

Hormones, hormones

Estrogen, progesterone are two more of the hormones

Adrenal makes adrenaline

Fight or flight that comes from them

Pancreas makes insulin

Milk begins with prolactin

Hormones, hormones

The quantity is so tiny but you need all your hormones

Thyroid and the ovaries

Pituitary and the testes

All the glands they do secrete directly in the bloodstream

Hormones, hormones

Stimulate body functions:

The duty of your hormones


Teacher's Activity Student's ActivitySteps to be

followed

Warm up

Students will together have a

peer group discussion on

whether organisms show

similar or different responses

in accordance to their body

structures.

Worksheet 1a

Worksheet 1b

Organisms

respond to

changes in the

environment

The teacher will put up questions

before students:

How are the various activities of

bodies of various organisms

regulated in response to other

individuals and environment?

The teacher would, then, explain

how control and co-ordination (or

response to stimuli) helps the

living organisms to survive in the

c h a n g i n g c o n d i t i o n s o f

environment around them.

Activity 1a: Concept of Stimulus

Activity 1b: Responding to

Balancing Challenges

Activity 1c: Responses to Abiotic

Factors in an Ecosystem

Pre Content

LESSON TEMPLATE : CONTENT AND COORDINATION

Students will conclude from

the day's session that response

to stimuli is a characteristic

proper ty o f the l iv ing

organisms.

They also understand that

both plants and animals react

to the various stimuli around

them. The method of reacting

to the stimuli is different and it

is usually in the form of some

Stimulus The teacher would start her

session by explaining that any

change in the environment to

which an organism responds and

reacts is called stimuli.

She would take an example of

amoeba to explain the concept of

stimuli.

Activity 2: Organisms react to

various stimuli


movement of their body part.

Worksheet 2

Content

http://www.youtube.com/watc

h?v=7pR7TNzJ_pA

Students understand that

most of the plant movements

usually occur due to unequal

growth of plant tissues in two

regions, which is also as a

result of phyto-hormones.

Plants respond to

stimuli

In her next session, the teacher

would emphasize that plant

movements are largely brought

about by definite internal and

external stimuli.

She might ask her students:

Students will try to list the

v a r i o u s u s e s o f p l a n t

hormones.

They discuss that certain

chemical substances are being

manufactured which closely

resembles natural phyto-

h o r m o n e s a n d m a y b e

employed to control aspects of

growth and development.

They will in few groups collect

the information for following

artificial substances

a. Artificial auxins

b. Weed killer 2,4D

Some of them will also find the

role of hormones in plant

tissue culture.

Worksheet 3

Co-ordination in

plants

Comparing plants and animals,

the teacher would explain that as

plants do not have a nervous

system and sense organs like

animals have, they can still sense

changes in the environment.

The teacher would further go in

the depth of this topic and

explain that animals use both

nervous system and hormones

for co-ordination of various

activities. Whereas, growth and

other processes in plants are

controlled by plant growth

substances also called plant

hormones/phytohormones.

The changes in the environment

are sensed by the plants by moving

part of their body, instead of whole

body (as is the case of animals).

The teacher would them explain

the role of various types of plant

hormones in detail.

Activity 3: Phytohormones

(Plant Growth substances)


Further, they will recapitulate

what was taught by their

teacher. They discuss among

themselves that the direction

of p lant movements i s

determined by the external

stimuli.

Students will together prepare

a collage of 'tropism - a

directional movement' using

various cut out pictures.

They will form three groups

and advised by the teacher,

prepare projects on the

remaining three tropisms that

were introduced in the class.

Worksheet 4

Co-ordination in

animals

What type of movements do they

know that happen in plants, in

response to external stimuli?

She would explain the difference

between tropic and nast ic

movements.

She would further explain positive

and negative tropism. Students

might be given handouts in order

to explain five common stimuli

that plants are exposed in the

environment. These are light,

gravity, chemicals, water and

touch. She would explain in detail

about two types of tropisms and

encourage students to prepare a

project on the remaining three.

Activity 4 : Tropic movements in

plants

After completing the session,

the students will be able to

Recognize the need for control

and co-ordination in the body

of animals

Identify the organs and

s y s t e m i n v o l v e d i n

controlling and coordinating

various body functions

Get an overall view of

Nervous system in animals

Worksheet 5a

Worksheet 5b

The teacher would begin the

session by telling her students -

That unlike plants, control and co-

ordination in animals is brought

about by two systems -

(a) Nervous System and

(b) Endocrine System.

She would first explain the

nervous system in multicellular

animals, taking an example of

hydra.

Next she would enl ighten

students with divisions of

vertebrate nervous system giving

an insight into human nervous

system.


Activity 5a: Coordination in

Animals

Activity 5b: Nervous system and

endocrine system in animals

The student will be able to...

1. Understand that nerve cell

is the basic structural and

functional unit of nervous

system

2.. Identify the two main

types of neurons that are

found in the peripheral

nervous system.

3. Understand significance of

nervous system in human

body.

4. Understand how are

neurons able to transmit nerve

impulses from one part of the

body to another -

The Propagation of a Nerve

Impulse

Worksheet 6a

Worksheet 6b

Worksheet 6c

Human Nervous

System

The human nervous system

would be explained in detail,

emphasizing on the neuron -

structure and function.

She would check the knowledge of

her students:

(a) Whether they know that

neuron is the unit of nervous

system?

(b) Structure, function and

arrangement of neuron

(c) Types of neurons

(d) Nerve impulses

(e) How are nerve impulses

transferred from one neuron

to another in the nervous

system?

(f) How do nerve impulses

travel through the synapse.

Students would be encouraged to

compare the human nervous

system to that of functioning of a

school.

Activity 6a: Introduction to

Human Nervous System

Activity 6b: Nerve Cell the basic

unit of nervous system

Activity 6c: Transmission of

nerve impulses


The student will try to

recapitulate what was taught

in the class

They will form groups to

identify the components of the

central nervous system. Also

d i s c u s s t h e p e r i p h e r a l

nervous system

They will also discuss the

functions of the four main

parts (cerebrum, cerebellum,

brain stem, and

hypothalamus) of the brain.

Worksheet 7a

Worksheet 7b

Worksheet 7c

Organs of the

Nervous system

The teacher would go further in

her discussion of human nervous

system in explaining the various

organs that are present.

The main organs of the nervous

system are: brain, spinal cord and

nerves.

She would explain, in detail the

central and peripheral nervous

system. Brief insight about the

human brain would also be given.

She would explain reflex action

and reflex arc and then cite the

difference between a reflex action

and walking.

Activity 7a: CNS and PNS

Activity 7b: Significance of

Nervous System

Activity 7c: Reflex Action

Activity 7d: Synapse

Activity 7e : Concept of Action

Potential

Students will be able to relate

the changes in their body and

e m o t i o n a l l y w i t h t h e

hormones.

They will try to compare the

messages passed by nervous

and endocrine system

They will also understand the

structure and functions of

various endocrine glands,

more particularly role of

Chemical co-

ordination in

animals

The teacher would explain that

h o r m o n e s a r e c h e m i c a l

messengers that regulate the

biological processes in animals

also.

Next she would explain

characteristics and release of

various hormones.

She might ask the students..

(a) How does the endocrine

system co-ordinate our body

activities?


thyro id g land and the

endocrine and exocrine

function of pancreas

Worksheet 8a

Worksheet 8b

Worksheet 8c

Post Content

(b) How do the endocrine

system and the nervous

system work together?

(c) What is the difference

between endocrine and

exocrine glands?

The teacher would then discuss

the major hormones produced by

the human body and their

functions.

Activity 8a : Role of hormones

Activity 8b : Exocrine and

endocrine glands

Activity 8c : Feedback mechanism

of hormone action

Studnets are able to

understand that many

flowering plants use a

photoreceptor protein, such

as phytochrome or

cryptochrome, to sense

seasonal changes in night

length, or photoperiod,

which they take as signals to

flower.

Worksheet 9

Photoperiodism in

plants

The teacher would explain the

concept of photoperiodism in her

class. She would enlighten her

students with the role of a special

pigment, phytochrome.

She would explain how plant

hormones and phytochrome

pigment together are involved in

the control and co-ordination

between environment and plant

responses.

Activity 9: Regulation of

photoperiodism

Through the activities that

were performed in the class,

the students understand that

the brain is the highest co-

ordinating centre in the body.

Brain : Structure

and function of its

parts

The teacher would go in the details

of structure of brain and various

functions that are performed by its

parts.


They will list the various

functions performed by the

brain.

Together they will have an

open house discussion about

the structure and function of

spinal cord.

Next they will try to find the

function of nerve gas

Worksheet 10

She would encourage her students

to create a nervous system model,

working in pairs. Further, she

would ask them to act the roles of

various parts of the nervous

system.

Activity 10 : Human Brain

The students will understand..

That most commonly EEG is

used to show the type and

location of the activity in the

brain during a seizure.

It also is used to evaluate

people who are having

problems associated with

brain function.

Students will list the problems

that can be evaluated using

EEG.

These problems might include

confusion, coma, tumors,

long-term difficulties with

thinking or memory, or

weakening of specific parts of

the body (such as weakness

associated with a stroke).

Worksheet 11

EEG as an

important tool

The teacher would discuss an

important tool to detect brain

disorders.

S h e w o u l d e x p l a i n t h a t

Electroencephalogram (EEG) is a

measure of brain waves. It is a

readily available test that provides

evidence of how the brain

functions over time.

The teacher would enlighten with

the fact that Scientists first

captured and recorded brain

waves in dogs in 1912. By the 1950s

the EEG was used commonly

throughout the World.

The teacher would encourage her

students to watch a video in order

to further understand about EEG.

Activity 11 : EEG as an important

tool

Students will explore the role

of other sense organs.

They understand that as in

Sense Organs The teacher would finally tell

students that our senses make us

aware of changes in our


eyes, the ears convert the

sound energy (in vibrations)

into nerve impulses.

They further discuss that

when a receptor responds to a

stimulus, it sends the nerve

impulse to the brain, which

makes us aware of the

sensation.

Worksheet 12 : Hand outs

environment and in our own

bodies.

She would further explain that we

have sense cells which actually

respond to stimuli. The special

property of these sensory cells and

sense organs is that they are able to

convert one form of energy to

another.

She would emphasize that the

structures which can do this are

called energy transducers.

She would explain how eyes can

convert light energy into electrical

energy of nerve impulse.

Activity 12: Structure and

Function of The Human Eye


ACTIVITY 1A : CONCEPT OF STIMULUS

Activity:

Learning Outcome:

Content:

The students would understand the concept of stimulus and its corresponding response.

One characteristic that distinguishes living organisms from nonliving things is the ability to sense and respond to conditions or changes in the environment. Any substance or condition in the environment that causes an organism to react is called a stimulus. The reaction of the organism to a stimulus is called a response. Living organisms are able to sense and adjust to a variety of stimuli in the environment using special sensory receptors that help them detect changes in light, odor, sound, and textures. Sensory receptors can be as simple as the sensory cells in jellyfish that are connected in a net-like arrangement, or as complex as the sensory organs in humans, such as eyes, ears, or a nose.

Work with your group to complete two of the three activities that will further your understanding of how organisms respond to the stimuli in their environments.

Exploring the concepts of stimulus and response

The students would work in the group of 4, make a list of other things that serve as a stimulus, and beside that word or phrase, write the response they might expect.

Each of the students should show an example on your whiteboard.


ACTIVITY 1B: RESPONDING TO BALANCING CHALLENGES

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Student Activity :

Problem: Can you remain balanced for 30 seconds while standing on one foot?

1. Place a piece of tape or sticky note on the floor.

2. Take turns having one volunteer at a time try the following challenges while the rest of the group observes the event.

Challenges (30 seconds each)

Balance w/ one foot on the tape and both eyes open

Balance w/ one foot on the tape and both eyes shut

Balance w/ one foot on the tape, eyes open, and arms held tightly against your side

Slowly spin around 4 times, and then balance with one foot on the tape w/ eyes open

Slowly spin around 4 times, and then balance with one foot on the tape w/ eyes shut

3. Record the answers to the following 3 questions.

1. What did you observe as the volunteer tried to maintain a balanced position?

2. What actions did the person take to recover his or her balance?

3. Which challenge was most difficult? Why?

A Delicate Balance

Read and discuss the following passage.

Have you ever watched a gymnast walk on a balance beam? With each step, the gymnast must make small balancing movements similar to the ones that you made when balancing on the piece of tape. Years of training and practice help the gymnast make very small balancing movements to avoid large over corrections that might cause a loss of balance. This allows the gymnast to give a smooth, balanced performance.

The semicircular canals in our inner ears contain tiny hairs that help us maintain balance or equilibrium. Gravity plays an important role in balance. The tiny hairs can be

Procedures:


moved by fluid as it is pulled downward by the force of gravity when our head changes position quickly. Nerves carry the message from the hairs to the brain, which causes the body to react and regain balance. This might cause a dizzy or spinning sensation, especially when sight is not being used to help the body as it maintains balance.

Most living things thrive in a balanced environment, and can tolerate a very narrow range of changes in their external environment without suffering harm or death. In order to survive, living things must constantly make adjustments to keep internal conditions constant and balanced, in spite of changes that occur in the external environment. For example, when warm-blooded animals are in cold temperatures, they may respond by shivering to increase body temperature by muscle movement. They also may develop "goose bumps" by making hair stick out straight to trap a layer of air for insulation. In extremely hot temperatures, animals may respond by sweating or panting to cool off. These responses automatically occur when body temperatures rise above or fall below the animal's most favorable temperature range.

Plants have different types of response than animals, because plants have different needs. Light is one of the most important abiotic factors in a plant's environment because it is needed for photosynthesis. Plants have special growth chemicals that will cause a plant to grow toward light, even if it causes stems to have a sideways growth.

Many animals, including humans, also respond to light. Work with your group to conduct the following investigation.

Problem: How do human eyes respond to varying amounts of light?

1. Position a flashlight so that the light shines toward a volunteer, but not directly into his or her eyes. Observe the volunteer's eyes as he or she looks toward and away from the light.

2. Trade positions so that the volunteer can make observations of someone else's eyes as they respond to light.

1. Describe the response of the volunteer's eyes to the light.

2. What is the relationship between the amount of light and the pupil size?

3. Why does the eye respond to light in this way?

Procedure:

Questions:


ACTIVITY 1C: RESPONSES TO ABIOTIC FACTORS IN AN ECOSYSTEM

Place a check mark in the box that best represents the stimulus for each response listed. Be prepared to justify and share your results with the class.


WORKSHEET 1A

Directions: Answer the following questions.

1. A stimulus is

A. something that causes a stimulus

B. something that starts to respond

C. something that causes a response

D. something that starts a stimulus

2. A response is

A. the reaction caused by a stimulus

B. the reaction to an event

C. the reaction to an occurrence

D. all of the above

3. A waste treatment plant is located near a bayou, which houses many types of flying fish. The plant receives a majority of its water from the bayou. During warmer months, the amount of flying fish decreases by 6%. Which of the following provides a reasonable stimulus for the decrease in flying fish population in the bayou?

A. The flying fish don't like the loud sounds of the machines in the waste treatment plant.

B. More water is used by consumers during warmer months, which decreases the amount of water the flying fish can live in.

C. Less water is filtered by the water treatment plant during warmer months, allowing the fish to travel upstream.

D. None of the above are reasonable stimuli.

4. Match the stimulus on the right with the corresponding response on the left:


Stimulus Response

I. The wind blows. A. My dog barks at the mail man.

II. The mail man comes in my yard. B. I answer the phone.

III. A cat hears a can opener. C. The students raise their hands.

IV. A phone rings. D. A tree limb falls down

V. The teacher asks a question. E. The cat runs into the kitchen.

Resource: http://teachhouston.uh.edu/

Students will be able to understand that -

(a) Response to stimuli is a characteristic property of the living organisms.

(b) both plants and animals react to the various stimuli around them.

(c) The method of reacting to the stimuli is different and it is usually in the form of some movement of their body part.

The scientific name of the most commonly found Amoeba is Amoeba proteus. It belongs to the domain Eukaryota and kingdom Protista. It is classified under the phylum Plasmodroma and order Amoebida. Amoeba has a typical shapeless structure and its movement depends on its changing body structure. Amoeba movement takes place by change in the nature of cytoplasm and formation of peculiar structures known as pseudopodia.

Amoebas are uni-nucleated, unicellular species. They are sometimes visible through naked eye while few species are too small to be seen with naked eyes. Few species are approximately grape sized. They respire by passive diffusion through their porous bodies. Most amoebas are free pond water species. They can be freshwater or marine. They have an adaptive mechanism called osmoregulation. The contractile vacoules present inside their body help maintain osmotic balance (they store the excess water

ACTIVITY - 2 : ORGANISMS REACT TO VARIOUS STIMULI

Learning Outcome :

Content :

Characteristics of Amoeba


and diffuse it through the pores, thus their bodies do not burst due to hypotonicity) when they are found in freshwater. Amoebas are heterotrophic in nature and they ingest food by the mechanism of phagocytosis.

The movement of amoeba is governed by a scientific theory known as Sol-Gel theory. Amoeboid movement is dependent on its anatomy. The cytoplasm inside the cell is capable of changing into different forms i.e. from fluid to solid and vice versa. When the cytoplasm is in fluid state, it is known as plasmasol and the more solid or gel like state is called the plasmagel. The interchange of plasmasol to plasmagel is known as Sol-Gel theory and is responsible for amoeba movement.The amoeba propels itself when the plasmasol flows through the center of the body towards its front and when it moves towards the sides of the body, it becomes solid again. When the cytoplasm is in solid or gel like state, there is no locomotion. Movement takes place only when the cytoplasm is in fluid state. This way the amoeba "drags" itself and this movement is known as amoeboid movement.

One more interesting fact about amoeba movement is the typical mechanism of locomotion by formation of protuberances from their body known as peudopodium. They are tentacle like extended structures meant not only for locomotion but also for capturing prey. The number of peudopodia they form ranges from one to dozen. They are also called false feet and can develop from any part of the body. The pseudopodium grows and engulfs its prey by phagocytosis. They shrink when the process is over. They also play a clever trick for capturing their prey by forming "blob". They form different shapeless structures and engulf their prey. They are also capable of detecting an agile organism or a slow moving specie.

From the above facts we come to know that amoeba movement is dependent on changes in environment. Amoebas can detect sense of stimuli and respond to the changes accordingly.

Students would be advised to share their views after having watched a video on amoebic movements ‘http://www.youtube.com/watch?v=7pR7TNzJ_pA'

Amoeba Movement


WORKSHEET 2

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A bright light shines into your eyes

stimulus: intensity of light

receptor: ______________________

transmission: neurons in CNS (brain)

effector: iris muscles

response: iris expands to reduce ______size, allowing less light to enter eye

You hear a sudden loud noise

stimulus: _______________________

receptor: mechanoreceptors (sensory neurons) in ears

transmission: neurons in CNS (brain)

effector: e.g. adrenal glands

response: adrenaline output increases ____________ (fight or flight-readiness for emergency)

You stand on a sharp object

stimulus: pressure of sharp object

receptor: ________________

transmission: interneuron in CNS

effector: muscles in upper leg

response: ___________________

You are hungry and smell dinner cooking

stimulus: ________________ suspended in the air

receptor: chemoreceptors in lining of nasal passages

transmission: interneurons in CNS

effector: salivary glands


response: release of _____________ into mouth cavity

2 ____________responses are automatic responses that occur rapidly and without conscious thought. This nerve pathway is part of the sympathetic division of the ______________c nervous system. During a reflex response a ___________ triggers a sensory neuron to send a nerve impulse to the __________________. The nerve impulse is transmitted to an interneuron and then to a _________ neuron. The motor neuron triggers a response in ___________ tissue.

3 _____________responses act to remove the body or part of the body from a potentially dangerous situation, protecting it from further damage.

Students will be able to understand the function of various plant Hormones and their effect on plants.

Ethylene is a hormone produced by most fruits; it is a colorless gas with the chemical formula H2C=CH2 (the carbons are double-bonded). Ethylene is lighter than air, which makes it diffuse rather rapidly. When a fruit is exposed to ethylene, it ripens at speeds faster than it would without.

Student Activity 1 :

6 unripe (green) bananas- In this case we will be using baby bananas

A large Ziploc™ plastic bag

Tincture of iodine-10% iodine dissolved in 90% ethyl alcohol Knife

1. Make sure all bananas are about equally unripe by counting the number of black/brown spots on the unripe banana. Make sure the bananas are not excessively covered with spots or bruised.

ACTIVITY - 3 : PHYTOHORMONES (PLANT GROWTH SUBSTANCES)

Materials Required :

Learning Outcome:

Content :

Procedure :


2. Look at two of the green bananas. Count how many brown/black spots there are that are larger than 2mm in diameter. Average the sums together and record the calculation on the chart under "Number of Spots."

3. Now, peel the two bananas. Take a knife and slice a small piece off the tops. Mash them with a spoon until it's a paste; try to make sure there are no large chunks. Now drip three drops of iodine onto each of the pastes. Roughly estimate what percentage of the iodine reacted with the banana pastes; reacted iodine will turn a dark blue or black color when introduced with ripe banana, while un-reacted iodine will stay amber showing that the banana is unripe. Average the percentages and put your results in the table. Also take note of any features of interest. Then dispose of these bananas.

4. Next, take a Ziploc™ bag. Place two bananas in it; seal it completely. Make one puncture (using a knife or other sharp object) at the top of the bag. Do not rip the bag. The puncture must not be too big (1-2mm wide). *This is to allow oxygen into the bag, which is required for the reaction to take place, but to also prevent a large amount of ethylene from escaping*Now, put it in an area that is well ventilated and has moderate lighting.

5. Now place two bananas in the same spot area as the bananas in the Ziploc Bag. These are the controls, which will be in an environment with less ethylene.

6. Leave the bananas in their environment for three days.

7. Remove the bananas from their environment and perform the spot test and the iodine test described above.

8. Compare the results from the unripe bananas to the bananas left in the open and the ones in the Ziploc Bag.

9. Data Tables

Type of Banana Unripe In Open Space Inside Ziploc Bag

Spots

Iodine Reaction

Other Notes


Student Activity 2:

Content :

Procedure :

Charles Darwin in 1880 exposed seedlings to light and charted how they bent toward the light only if the tips were exposed to light. He exposed grass to light and noted that it curved toward the source. He covered the top of the seedlings with light proof caps, no bending occurred. He wasn't quite sure what was going on.

Boysen-Jensen's study between 1910-1913 with beheaded seedlings, demonstrated that placing a bit of gelatin on the stump, replacing the top on the gelatin, caused curvature toward light to occur just as with intact seedlings. If the tip is not replaced, curvature does not result.

Paal (1918) demonstrated that if a cut tip is replaced off center growth results and it will be curved.

The reason for the bending of plants toward light is that growth hormones called "auxins" on the non-illuminated side will cause the plant to grow more than on the illuminated side. Since the elongated cells on the non-illuminated side will grow faster than on the other side, the plant will bend. It looks as if the plant is moving toward light to make food, but no plant can seek anything. The higher concentration of auxins on the darker side stimulate growth. Growth responses resulting from external stimuli are termed tropisms and since this has to do with light (photo=light) this is called phototropism.

1. In the first part of the lab, students will duplicate Darwin's and Boysen-Jensen's experiment. They will utilize three similar seedlings. They need to cut the tips off of two seedlings, cover the tip of one with a cap (have them experiment on how to do this), leave the other plant with the cut top exposed, and leave the last seedling as a control. Remind students how a "control" is used. A control represents what will happen if nothing is done at all. This is used to compare whether an action has an effect or if it is due to chance.

2. In the second part of the lab, students will set up an experiment that determines how long it takes different plants to "bend." They need a geranium, a seedling (tomato, or other vegetable), and an ivy (using different plants are acceptable).

3. Students will plant the rooted geranium and ivy in new containers and need to place the plants in the same general area. Over the next week, they will observe how the pants grow in light. The experiment will proceed quicker if you have an


area of intense light that the plants will turn towards. They will notice that some plants take longer to bend than others.

4. Record your observations.

Duplicate Darwin’s and Boysen-Jensen’s experiment as described by your

teacher. Describe what you did and record what happens on each day that you observed the plant with and without a cap, and with no top.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

Day Day Day Day

NO CAP

CAP

NO TOP

Plant rootings as described by your teacher. Make sure that you water the

plants and that they are all in the sample place. Describe how they bend for one week.

DAY OF OBSERVATION

TYPE OF PLANT 1 2 3 4 5 6 7

CONCLUSIONS : Is there a difference amongst the plants?

__________________________________________________________________________

__________________________________________________________________________

Procedure :

Exercise 1.

Exercise 2 :


WORKSHEET : 3

1. Name and describe the five major classes of plant hormones.

Class of Plant Hormone Where it is made How it is transported Responses it causes

2. Define the term plant hormone.

3. Provide an example of how a single aspect of growth and development may be influenced by several hormones.

4. Calcium influences several effects of plant hormones. Why, then, isn't calcium considered a plant hormone?

5. Provide an example for each of the following generalizations:

a. A single plant hormone can produce many effects.

b. The effects elicited by a hormone depend on many factors, including the presence of other hormones.

c. Hormonal responses probably result from changing ratios of hormones rather than from the presence or absence of an individual hormone

6. Gibberellins, cytokinins, and auxin all promote growth. How would you distinguish them from one another?

7. What is the adaptive significance of increased ethylene production in response to wounding and stress?

8. Home gardeners commonly pinch off the shoot tips of certain plants in order to promote fuller, bushier growth. Explain why removal of the shoot tip should promote such growth.

9. In what way is ethylene a unique plant hormone?


10. What is phototropism and which hormone is involved in this phenomena? What is the adaptive significance of phototropism?

11. Define photoperiodism and describe its adaptive significance.

12. What causes leaves to change color in the fall and senescence?

13. Describe structural and chemical changes that may occur in a plant as it begins dormancy. What triggers this decrease in metabolism? What influences the resumption of metabolic activity?

14. Many plants produce seeds that require a period of dormancy before they will germinate. Of what value is the dormancy to the plant? Where might you expect to find plants with seeds that do not undergo dormancy?

15. What is the adaptive significance of thigmomorphogenesis and gravitropism?


ACTIVITY - 4 : TROPIC MOVEMENTS IN PLANTS

Student Activity:

Learning Outcome:

Class Discussion:

Skit:

Students would understand the control mechanisms in plants.

What happens when the leaves of a touch-me-not plant are touched?

When the leaves of a touch-me-not plant are touched, the plant uses electrical-chemical means to convey this information from cell to cell.

Plant cells at the leaf base change their shape by changing the amount of water in them.

This results in folding and drooping of leaves.

Growth dependent movements or tropic movements are slow, occurring either towards or away from the stimulus. The movement of plants in the direction of stimulus is known as 'tr opis m'. Tropic movements are shown in response to environmental factors such as light, gravity, water and chemicals. Plant roots are positively geotropic and negatively phototropic whereas plant shoots are usually negatively geotropic and positively phototropic. Pollen tubes show chemotropism by growing towards the ovules.

Students will prepare a skit to show different kind of tropism.

1. Growth of tendrils: When a tendril comes in contact with a support, then the part of the tendril away from the support grows more rapidly than the part of the tendril that is in contact with the object, thus the tendril circles around the object and appears to cling to it.

2. Phototropism: Directional movement of a plant/plant part in response to light, for example: shoots show positive phototropism.

3. Geotropism: Directional movement of a plant/plant part in response to gravity, for example: roots show positive geotropism.

4. Chemotropism: Directional movement of a plant/plant part in response to chemicals, for example- growth of the pollen tube towards the ovule.

5. Hydrotropism: Movement of a part of a plant in response to water.



Pair Share Activity: Discuss the tropic movement shown below:

____________________________________

____________________________________

____________________________________


____________________________________

Q1. How does phototropism occur in plants?

Q2. How does chemical coordination occur in plants?

Q3. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?

Q4. Design an experiment to demonstrate hydrotropism.

WORKSHEET 4

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SCIENCE UNIT-2 BIOLOGY

ACTIVITY 5A: COORDINATION IN ANIMALS

2

2

2

Learning outcomes:

Content:

After completing the session, the students will be able to:

Recognize the need for control and co-ordination in the body of animals.

Identifies the organs and system involved in controlling and coordinating various body functions.

Have an overall view of Nervous system.

The nervous system is a communications network that helps animals adjust to their environment. The three main parts of the system are the brain, the spinal cord, and the nerves. The brain can, at times, be compared to a computer in that it processes incoming information, sends instructions back out through pathways. These pathways are the nerves.

The brain is the processing center. It has three main parts:

1) the cerebrum, which is the largest,

2) the cerebellum, and

3) the medulla oblongata.

The spinal cord runs down the center of your back, is protected by the spinal column, and contain 31 pairs of nerves coming out of each side. If a pathway of nerves is severed, a part of the body will not receive a signal, and consequently will not work.

Nerve cells are called neurons. Nerve cells that move information to the brain are called sensory nerves, while neurons that move information away from the brain are called motor nerves. An action that takes place without thinking is called a reflex action. Reflex and involuntary actions, such as heartbeat, are controlled by the autonomic nervous system.

The main functions of the nervous system are to:

1) control muscles and tissue,

2) control organs,

3) control senses, and

4) control thinking

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Student Activity: A (3-5 minutes)

Student Activity B:

Introductory Attention-Getter :

I. Teacher will create a loud noise, without warning, causing students to exhibit reflexes.

II. Students will be asked:

A. What kind of reactions did you have? (eyes blinked, jumped out of seat, felt heart skip a beat, etc.)

B. Do you know what these involuntary reactions are called? (reflexes)

C. What inside your body causes these involuntary reactions to occur? (nerves or nerve impulses; nervous system)

D. Why these involuntary reactions are important for living beings?

III. Transition to lecture: "Reflexes are one important feature of the human nervous system.

Activate the students with two different student activities - In the Hot Seat and Technology Vocabulary Learning.

(1) In the Hot Seat - 5 minutes

Purpose: To motivate student learning

Description: In this activity, several students will be asked to sit in the "Hot Seat" and answer questions related to the topic of study.

Q1. What is the "control center" of the nervous system?

Q2. What runs throughout your body and "tells" your muscles to move?

Q3. Where is the "super highway" of nerves that comes from the brain located?

Q4. What is the term for a movement that does not require thought?

Q5. If you're in pain, those signals run from your nerves to where?

Technology Vocabulary Learning: Through classroom organization activity, the teacher would explain the concept of human nervous system

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Cognitive Teaching Strategies

Outline of lecture:

The teacher would give brief outline on parts of the nervous system, specifically highlighting the new vocabulary. Vocabulary will include: brain, nerves, spinal cord/column, cerebrum, cerebellum, medula oblongata, reflex, autonomic nervous system.

The nervous system is a communications network that helps animals adjust to their environment. The three main parts of the system are the brain, the spinal cord, and the nerves. The brain can, at times, be compared to a computer in that it processes incoming information, sends instructions back out through pathways. These pathways are your nerves.

The brain is the processing center. It has three main parts:

1) the cerebrum, which is the largest,

2) the cerebellum, and

3) the medulla oblongata.

The spinal cord runs down the center of your back, is protected by the spinal column, and contain 31 pairs of nerves coming out of each side. If a pathway of nerves is severed, a part of the body will not receive a signal, and consequently will not work.

Nerve cells are called neurons. Nerve cells that move information to the brain are called sensory nerves, while neurons that move information away from the brain are called motor nerves. An action that takes place without thinking is called a reflex action. Reflex and involuntary actions, such as heartbeat, are controlled by the autonomic nervous system.

The main functions of the nervous system are to:

1) control muscles and tissue,

2) control organs,

3) control senses, and

4) control thinking.

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Classroom organization: Students will be grouped into 4 groups of 3 students each. There would be 5 stations set up throughout the room: Computer Central, the Human Machine, Anatomy Study, Frankenstation, and Research Corner. The students will spend roughly 15 minutes at each station. If a group or student finishes early, they may go back to a station that was not completed, or browse Human Body reference materials.

1. Computer Central - Students will use a search engine, e.g., Yahooligans, to find diagrams of the brain or nervous system. Once the students find an acceptable image, they will copy and paste the image into a text box on a word document. These pictures will be printed, cut out, and added to our body board. If they finish this activity, the students will go to the website, "Your Gross and Cool Body," and read the information on the nervous system.

2. The Human Machine - This center is dedicated to hands-on activities and experiments. Students will perform two experiments, one based on perception, the other, sight. Both these experiments are given in the form of worksheets.

3. Anatomy Study - Students will view diagrams from various expository texts in order to draw and label a sketch of the human brain and spinal column. While at this station, students will also label two index cards. Card one will contain an organ that is part of this system, while card two will list the function of that organ. These cards will be placed on the classroom body board.

4. Frankenstation - Students are in the process of "cloning" themselves, by coloring different body organs and adding them do an outline of their own bodies. This lesson will find them coloring and adding a brain.

5. Research Corner - Students will be given a 3 x 3 vocabulary worksheet with terms related to the nervous system. They must make 6 sentences using the words provided, by relating the three words across each row and down each column. Research materials such as Research cards and expository texts will be provided, so that the students can practice the skill of finding information through print media.

Brace Map

Students will complete a brace map on the parts and functions of the nervous system (see Brace Map in Resources). The brace map is one member of an array of graphic organizers called Thinking Maps. The Thinking Map series was developed by the

Explaining the center activities:

Summary Strategies

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Innovative Learning Group, 1995. The purpose of the brace map is to break down a system from whole to parts, and the format for our map was created using Inspiration Software.

Pictures of Displayed Information

http://its.guilford.k12.nc.us/act/grade7/act7.asp?ID=841

http://yucky.kids.discovery.com/body/

http://yahooligans.yahoo.com/science_and_nature/living_things/biology/Anatomy/m

http://www.google.com/image

Online resources:

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WORKSHEET-5A

WORKSHEET : 5B

Experiment 1

Experiment 2 : Perception

Question:

The Vanishing Ball - "Looking" at the optic nerve

1) In the center of the paper, draw two, round (6mm), colored dots 4 inches apart.

2) Hold the paper at arm's length from your face

3) Close your right eye and look at the dot on the right side with your open eye

4) Slowly move the paper toward your face. Be sure to concentrate on the right dot and do not look at the one on the left

5) Stop moving the paper when the dot vanishes

1) Soak one pipe cleaner in the bowl with cold water, and soak the other in a bowl with very warm water

2) Quickly remove the pipe cleaners, fit them together, and place them on the table.

Surprise!! What sensation did you feel?

Label the major organs in the nervous system diagram.What is their function, and how do they perform in relation to the rest of the Human Machine?

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WORKSHEET : 5C

3 x 3 Vocabulary - The Nervous System

Students will write six sentences, which illustrate the relationship between the words in column 1 down, 2 down, 3 down, and rows 1 across, 2 across, and 3 across. In other words, use all three words in the top row in the same sentence. Then, do this with the other rows and columns.

Column 1 Down:____________________________________________________________

___________________________________________________________________________

Column 2 Down:____________________________________________________________

___________________________________________________________________________

Column 3 Down:____________________________________________________________

___________________________________________________________________________

Column 1 Across:___________________________________________________________

___________________________________________________________________________

Column 2 Across:___________________________________________________________

Column 3 Across:___________________________________________________________

___________________________________________________________________________

cerebru cerebellum

medulla

oblongata

hemispheres nerves reflex

memory

muscles

spinal

cord

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WORKSHEET : 5D

WORKSHEET 5E : THE HUMAN MACHINE AT WORK (ACTIVITY)

ACTIVITY - 5B : NERVOUS SYSTEM AND ENDOCRINE SYSTEM IN ANIMALS

Anatomy study- Draw and label a sketch of the human brain in the space provided.

1) On an index card, list an organ in this system that is not already present.

2) On a separate card, list a function of this system, and add it to our board.

Demonstrate the interdependence of systems through

writing. Describe an example of how your nervous system consciously and unconsciously controls the organs of another body system. After describing your examples, share them with the other group members.

The students will be able to compare the messages passed by

nervous and endocrine system

Nervous System vs. Endocrine System: Time of message delivery

The nervous system is much like a phone call. We dial in the number (which is the 'receptor' for who we want to talk to) and we get to deliver our message instantly to the person.

The endocrine system is much like using the post office ('snail mail' as it is referred to in this day). I will mail a letter to 'Julie Thompson' (Teachers..pick the name of a student in class...this makes the example more apart of their world.) and in order to get this letter to her, I must place her address on the envelope. The address is now the 'receptor' for her house. I place the letter into the 'circulation' of all letters in the area. Her 'address' helps the postal office find her house in a couple of days to deliver the message.

Now...much like the postal office's options of priority and express mail, the endocrine system can also speed up delivery of certain messages based on importance.

The nervous system uses direct wiring (neurons) to communicate to the tissue and the endocrine system uses chemical messengers (hormones) that use the blood circulation to deliver their instructions.

Resource: www.tutorvista.com/.../endocrine-system.php

Body Board:

Doctor's Diagnosis -

Learning Outcome:

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WORKSHEET : 5B

1. Compare the regulatory mechanisms of the following system. Give the chemicals involved in both.

Q5. How do auxins promote the growth of tendril around a support?

177


ACTIVITY 6A: INTRODUCTION TO HUMAN NERVOUS SYSTEM

Learning Objectives:

Content :

The student will be able to understand the general organization

of the human nervous system.

In this unit, the students will understand the structure and functions of various organs of the Nervous system. They would be able to have a comparative study of Nervous system with an organization which would lead them to an understanding of Nervous system as a complete system. The nervous system consists of the brain, the spinal cord, and the network of nerves throughout the rest of the body. It is sometimes called the master system, since it regulates and coordinates every other body system. The nervous system provides a rapid means for the various parts of the body to communicate with each other. It allows us to adjust to the world around us and cope with the challenges of life. It influences how we act or react to stress. The fight or flight response is a good example. This is a hormonally stimulated state to prepare the body for an upcoming threat or challenge.

The nervous system is composed of two major parts; the central nervous system (CNS) and the peripheral nervous system (PNS). The central system is the brain and spinal cord, and is where most information is processed. The peripheral system is the network of nerves throughout the rest of the body. The peripheral nervous system allows signals to travel between the central nervous system and the body's sensory receptors and motor effectors, such as the muscles.

1. The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts.

2. The Central Nervous System (CNS) consists of the brain and spinal cord.

The Human Nervous System.

3. The CNS and PNS are anatomical divisions of the nervous system. The nervous system is also divided into two physiological (or functional) divisions -- a voluntary system, which as the name implies is concerned with voluntary actions such as muscle movement; and an involuntary or automatic system referred to as the autonomic nervous system

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Student Activity 1: Analogy

The students would do a comparative study of the Nervous system with an organization/school. They would compare each part of the Nervous system, understand its function and relate it with their study. They would also understand its importance for cell survival. They can do the same in a group of two.

Brief information of the functions of organs of Nervous system

should be given to the students. An example is given below

The Nervous system is compared to a school

Teacher support:

Organs of Nervous system

Function Department in school Function

Brain center of all commands and monitors all the processes of the body

Office of the Principal

center of all commands and monitors all the processes of the school

Spinal chord to relay all the impulses, information and sensations to and from all around the body, to and from the brain.

Vice Principal, Co-ordinators and administrative officers

To communicate all information's to and from the office to and from all the stake holders of the school.

Peripheral Nervous System

information from the body to the spinal cord and from the spinal cord to the body

Wires of telephones or messengers

Carry messages both ways

Sensory neurons providing the CNS all the information regarding the environment

Meetings with students and staff

Helps to improvise the teaching learning process through proper feedback of students

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Motor Neurons Help the body react to different environments

Circulars ,notices, messages

To help office send information to all stakeholders

Muscles and Glands

Site of action Classrooms are the area of activity

Teaching and learning /transaction

Sense organs help brain in knowing more about the external factors.

Mail, calls, meetings, complaints and suggestions

To help office receive Feedback from stake holders

The students after completing the activity can come up by turns and present their analogies. This can be followed by a brain storming session on classification of various other departments/parts.

Student Activity 2: Students prepare a 3-D model of the nervous system on organs using jelly, etc and demonstrate the importance of each.

They can have a role play where they can enact one organ and present its function. Teacher support: Students are made aware of the structure of all organs .

Group Activity : Students are divided into two groups. One group carries placards of names of organs of Nervous system. The other group carries the functions they perform. The students would be blindfolded and have to find their corresponding pair.

Teacher Support : The students need to have a prior knowledge of the functions of organs.

Student Activity 3:

Student activity4 :

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WORKSHEET : 6A

2

2

2

2

2

2

Answer the following

Answer the following long questions

1. List three ways the human brain is similar to a computer.

2. List the four lobes of the brain.

3. List a function of each of the four lobes of the brain.

4. List the two major divisions of the nervous system and describe the difference between the two.

5. What are the three main functions of a nervous system?

Sensory Input, Integration, Motor Output

6. What structures comprise the Central Nervous System (CNS)?

brain and spinal nerve cord in vertebrates

7. Motor output is the conduction of signals from the ____CNS_________ to the _____effector cells such as muscles_________.

8. Signals are conducted by ____nerves_____________ which are bundles of _____neurons_______ wrapped in connective tissue.

9. Sensory and motor neurons are collectively called the ______peripheral nervous system__.

10. The structural and functional unit of the nervous system is the _________neuron____________.

How big is the human brain?

What are the organs of the Nervous system?

What does the brain do?

How long is the spinal cord?

How fast does the nervous system work?

What does the brain control?

181


ACTIVITY 6B : NERVE CELL THE BASIC UNIT OF NERVOUS SYSTEM

Learning outcomes:

Content:


1. Understand nerve cell as the basic structural and functional unit of nervous system

2. Identify the two main types of neurons found in the peripheral nervous system.

3. How nerve cells are similar and different from other cells of the body

The Nerve Cell : The basic unit of the nervous system is the nerve cell, or neuron. The basic function of the neuron is to transmit information. There are approximately 28 billion neurons in the human body penetrating every tissue and in every part. Neurons vary greatly in size and shape, with the longest ones-those that extend down the leg as part of the sciatic nerve-measuring over one meter. All nerve cells

have a similar structure.

The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process. The human brain has approximately 100 billion neurons.

182


Neurons come in many different shapes and sizes. Some of the smallest neurons have cell bodies that are only 4 microns wide. Some of the biggest neurons have cell bodies that are 100 microns wide. (Remember that 1 micron is equal to one thousandth of a millimeter!).

Neurons are similar to other cells in the body because:

1. Neurons are surrounded by a cell membrane.

2. Neurons have a nucleus that contains genes.

3. Neurons contain cytoplasm, mitochondria and other organelles.

4. Neurons carry out basic cellular processes such as protein synthesis and energy production.

However, neurons differ from other cells in the body because:

1. Neurons have specialized extensions called dendrites and axons. Dendrites bring information to the cell body and axons take information away from the cell body.

2. Neurons communicate with each other through an electrochemical process.

3. Neurons contain some specialized structures (for example, synapses) and chemicals (for example, neurotransmitters).

A Simple Neuron Model

Here's the most simple model of a neuron I can think of...and you don't need any supplies. It's your hand! Hold out your arm and spread your fingers. Your hand represents the "cell body" (also called the "soma"); your fingers represent "dendrites" bringing information to the cell body; your arm represents the "axon" taking information away from the cell body.

Cooperative Learning Activity: (8-10 minutes)

I. Students will assemble in groups of three

A. One group member will be the recorder (write thoughts and ideas on paper)

B. One group member will be speaker for the group in whole-class discussion

C. One group member will be a "manager" (make sure things are moving along)


Student Activity 2:

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II. Each group will be asked to...

A. List 3 or 4 locations where sensory receptors can be found on or inside our bodies (try to think of at least one that is not related to a sense organ). Possible answers: on our skin-for temperature changes; all tissues and organs (except bra in) - for pa in ; on our musc les - for pressure and musc le contraction/relaxation; taste buds on tongue; receptors (olfactory neurons) in nose; receptors in ears.

B. If sensory neurons carry nerve impulses from sensory receptors to the central nervous system, what do you think motor neurons do? Answer: carry information from central nervous system back to the muscle, gland, and/or sense organ involved so it can respond to impulse delivered by sensory neurons.

III. Whole-class discussion of students' responses

"So basically, sensory receptors react to changes inside and outside of your body. Internally they detect things like changes in blood pressure, pain, or strain on muscles; externally they detect changes in light, sound, and temperature."

Summary/Conclusion (15-20 minutes)

I. Sensory and Motor Neurons: Partners in Transmitting Nerve Impulses (brief review)

A. Sensory - carry impulses from sensory receptors to CNS

B. Motor - carry information back to sensory receptors so muscles, glands, and organs involved can react appropriately

C. Spinal cord - sensory nerves go into it and motor nerves come out

II. Reflexes: "Special" Responses

A. Produce rapid, involuntary movement or response

1. Important in times of danger

2. Example: blinking of eyelid when insect approaches eye or when startled by unexpected loud noise (like at beginning of class)

Transition to Activity 4:


184


B. Why are reflexes so fast?

1. Involve few neurons

2. Many reflexes never reach brain; travel only as far as spinal cord

3. Example: blinking eyelid occurs before cerebrum is even aware of danger

III. Students exploring nervous system and mini-experiments on the Internet

A. Students will work individually on computers in the computer lab

B. Students will go to Neuroscience for Kids

(http://faculty.washington.edu/chudler/neurok.html)

C. Students will be able to...

1. Explore the entire human nervous system

2. Test mini-experiments and activities about the nervous system

3. Read current events dealing with neuroscience

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WORKSHEET : 6B

1) Use the words from the list below to label the following diagram of a neuron in the lines provided.

Word Bank Axon - Cell Body - Dendrites - Myelin

Node of Ranvier - Nucleus - Synaptic Terminal

186


2) Below is a list of different parts of a neuron. On the lines following each word, write out what that structure does for the neuron (its function) and where it is located on the neuron.

Axon:________________________________________________________________________

______________________________________________________________________________

Cell Body:_____________________________________________________________________

______________________________________________________________________________

Dendrites:____________________________________________________________________

______________________________________________________________________________

Myelin:_______________________________________________________________________

______________________________________________________________________________

Node of Ranvier:_______________________________________________________________

______________________________________________________________________________

Nucleus:______________________________________________________________________

______________________________________________________________________________

Synaptic Terminal:_____________________________________________________________

______________________________________________________________________________

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ACTIVITY 6C : TRANSMISSION OF NERVE IMPULSES

2

2

2

2

2

Learning Outcomes:

Content:


Explain how neurons transmit nerve impulses from one part of the body to another.

Understand the Propagation of a Nerve Impulse

Like many other cells of the body, neurons contain charged ions including potassium, sodium and chlorine. Potassium and sodium are positively charged ions whereas chlorine is a negatively charged ion. Unlike most other cells, neurons are able to depolarize, creating a nerve impulse, by rapidly changing the concentration of ions inside the cell relative to the outside of the cell.

When at rest, a neuron is polarized-that is, it has a negative charge on the inside of the cell relative to the outside of the cell. This is because it has a higher concentration of negatively charged ions on the inside. When stimulated, the nerve cell membrane becomes permeable to sodium ions, which rush in temporarily causing a positive charge to build up on the inside relative to the outside. For a short time afterward, referred to as the "refractory period," the nerve cell is unable to "fire" again. A mechanism in its cell membrane has to "pump" the sodium ions back out again, restoring the negative charge and the "action potential" to the cell. Once the action potential is restored the neuron is ready to transmit the next nerve impulse. This all takes place in a very short period of time, measured in microseconds, as a single nerve cell can fire hundreds of times during a single second.

Transmission of information in neurons

Dendrites receive messages from other cells axon fibers carry the impulse terminal branches of the axon synapse with another neuron, muscle, or gland

A neuron fires an impulse when it receives stimulus from sense receptors

Stimulation by heat, light, pressure, or chemical messages from neighboring neurons

Stimulation causes an increase of sodium (Na) into the cell, disrupting the cells resting

Potential

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Stimulus can be: Excitatory- or Inhibitory-

Threshold of excitation- the point where stimulus creates an impulse

The impulse is known as an action potential

Action potential- is a brief electrical charge that travels down the axon

Neural impulse travels at speeds ranging from 2- 200 mph

Measured in milliseconds (1/1000 s) computer activity is measured in nanoseconds

Myelin sheath- insulates the axons of some neurons and helps speed their impulses

Multiple Sclerosis (MS) : A disease in which the myelin sheath degenerates, causing a slowing of the all communication to muscles and the eventual loss of muscle control

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Nerve Cells Communication

Scientist once believed that the branching axon of one cell fused with the dendrites of another, uninterrupted

WE now know that the axon terminal of one neuron is in fact separated form the receiving neuron by a gap, called synaptic gap. The junction itself is the synapse.

This gap is less than one millionth of an inch wide!! Whoa.

Also called, "protoplasmic kisses"…awe, so sweet.

When the AP reaches the knoblike structures at the end of the terminal branches known as the __________________, it triggers the release of the chemical messengers, called_____________________

The nervous system (and how it communicates)

The structure and function of a neuron

Teacher Materials

poster of a neuron

stopwatch

picture of a hand

picture of a brain

mousetrap

dominoes

children's literature on neurons/nervous system

neuron handout

rolling pins

different colored clay

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Student Group Materials

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six labeled toothpick flags (reading nucleus, cell body, dendrites, axon, myelin sheath, axon terminals; pre-made by teacher)

one button

one pipe cleaner

5 pieces of ziti macaroni

one piece of construction paper

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Handouts

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Figure 1: A teacher guide and notes for the activity.

Figure 2: An individual student handout for the activity. This includes a diagram of a neuron with defined parts in simple, easy to read language.

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Figure 3: A Barnes student constructs and labels his neuron!

Figure 4: A student's completed neuron.

The kids will be shown a diagram of a neuron. The teacher(s), will point out the different parts and briefly describe what each part does. The teacher(s) will explain how a neural impulse is transmitted to the brain using the example of a hand touching a hot stove. (See Figure 1).

Then the kids will be given time to make their own neurons from different colored clay. Using the pre-made "flag labels," they will label the different parts-- cell body, nucleus, dendrites, axon, axon terminals, and myelin sheath. (See Figures 3 and 4).

The teacher(s) will have set up an oval made from upright dominoes (with 1 foot breaks in it). At one end will be a picture of the brain and at the other end will be a picture of a hand. Starting at the picture of the hand, the kids will take turns bumping the dominoes at each break to continue the dominoes falling as fast as they can. (The falling dominoes represent a traveling neural impulse. See "Domino Activity" Video). This part of the activity is timed with a stopwatch.

Procedure :

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After the kids have watched their "impulse" travel from the hand to the brain and back the teacher(s) will discuss how long it took them to complete the activity a n d c o m p a r e t h a t t o h o w f a s t a r e a l n e u r a l i m p u l s e i s . http://wikieducator.org/File:Teaching_bio_2.png

Lesson plan

Opening Questions

What is the nervous system? What does it do?

What is a neuron?

How do neurons work?

1. Before activity begins, make six "flag labels" for each student (using one toothpick and a small piece of white paper). The six labels should correspond with the 6 parts to be focused on: cell body, nucleus, dendrites, axon, axon terminals, and myelin sheath. Also before activity begins, set up domino apparatus described above.

2. Discuss the function of nervous systems-- to relay messages and control body functions. Discuss the role of a neuron as a "little messenger" of the system.

3. Show students the parts of a neuron (cell body, nucleus, dendrites, axon, axon terminals, and myelin sheath) using the large neuron poster. Explain each part's function. Show how a chemical message travels through a neuron.

4. Hand out student materials (including individual handouts) and have students construct their own neuron model. Clay is used to make the dendrites, cell body, and axon terminals, pipe cleaner for axon, ziti for myelin sheath, and a button for the nucleus. (See Figure 4).

5. After models are completed, ask students to stand behind one section of the oval domino apparatus.

6. Place a picture of a brain on the tailed end of the oval and a picture of a hand on another.


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7. After snapping the mousetrap on the paper hand (a teacher task ONLY), instruct one student to hit their row of dominoes as the stopwatch starts. Other students follow suit (knocking down their own row of dominoes in the oval). Watch as they fall around the table. (See "Domino Activity" Video).

8. Repeat step 7 if desired.

9. Ask students: How do the dominoes represent a message traveling through neurons? If needed, explain the process being sure to incorporate the brain and hand in the answer.

10. Clean up.

http://wikieducator.org/File:Little_messenger_handout.png

Wrap up comments/ Discussion Questions

Although our domino "message" seemed to travel fast, a real neuron can fire in 5 milliseconds. That's 200 times per second!

One neuron in the body can be connected to as many as 1000 other neurons.

Your brain alone has 100 billion neurons. And you have neurons everywhere in your body!

What did we learn?

What does the nervous system do?

What are the "little messengers" of the nervous system? What are its parts and what do they do?

Ask students for an example of how the nervous system works.

i.e. What happens when you step on a nail with your foot?

Maths connections

We will use a stopwatch to time how long it takes for the kids to "send the message" as fast as they can with the dominoes. Then, we will explain that in reality, it takes less than a second. Neural impulses travel at speeds from 1 to 120 meters per second.

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Literature connections

Several books can be used alongside this activity for student reference. They are:

Your Wonderful Body! by Joyce Hurwitz and Roz Schanzer

Getting to Know the Amazing Human Body by David Macaulay

Dr. Frankenstein's Human Body Book by Richard Walker

If students finish their neuron model earlier than others, these books can be consulted. They contain information on neurons and the nervous system in general.

Answer the following questions:

1. All cells have an electrical charge difference across their plasma membrane called the ____membrane potential_____________________________________.

2. The membrane potential exists because:

the different concentration of certain ions across the cell membrane.

3. The membrane potential of an unstimulated neuron is called the ____resting membrane potential________________________.

4. What makes invertebrates like squid and lobsters such good animals for the study of nerve impulses?

they are large in diameter

5. What is the principal + charged ion outside of a cell?

Na+

6. What is the principal + charged ion inside of a cell?

K+

7. How do these ions move across the cell membrane?

They must either be pumped by membrane proteins or by simple diffusion through ion channels.

8. In a neuron, an action potential can only be generated in the _____axon_________________.

WORKSHEET : 6C

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9. The action potential is a non-graded, all or non event; meaning ___magnitude of the action potential is independent of the strength of the depolarizing stimulus that produced it, providing the stimulus reached threshold depolarization level___.

10. The action potential arises because the plasma membrane has ___voltage-gated ____ ion channels.

11. Which two types of voltage-gated ion channels contribute to the action potential?

Na+ and K+

12. Which voltage-gated ion channel opens first and which one opens second in an action potential?

Na+ opens first and K+ opens second


1. Identify the components of the central nervous system and peripheral nervous system.

2. Explain the structure and functions of central nervous system

3. List the two parts of the central nervous system and their basic functions.

4. Discuss the functions of the four main parts of the brain.

The central nervous system is made up of the brain, spinal cord, and nerves. The brain has three main parts, the brain stem or medulla, the cerebrum, and the cerebellum. Each part has a special job to perform.

The medulla keeps your heartbeat and your breathing regular.

The cerebellum is in charge of balance and coordinating all of the muscles. The medulla and cerebellum work all of the time, even when we don't know it.

The cerebrum controls thinking, moving and sensing. It is in control when youread a book or play a game.

ACTIVITY 7A : CNS AND PNS

Learning Outcomes:

Content:

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The spinal cord is a long piece of nerve tissue that runs from the brain through the backbone. It connects the brain to the body's nerves. Nerves are tiny fibers that are in the spinal cord and throughout the entire body. Nerves pick up information and send it up the spinal cord to the brain. Individual nerves are in charge of seeing, hearing, smelling feeling, or touching something.

Certain nerves in the spine and brain tell parts of the body to act really fast. When the body must act very fast in order to avoid injury, the message from the sensory nerves doesn't go all the way to the brain before your body takes action. The message travels from the sensory nerve to the spinal cord and is sent back to a muscle right away. This quick action is called a reflex. A reflex is an action we take even before the brain knows about it.

A. Central Nervous System (CNS)

1. Brain and spinal cord

2. Body's control center

a. Organizes incoming information from sensory organs and receptors

b. Issues outgoing commands to various parts of the body

3. Connected to rest of body by nerves that make up the...

B. Peripheral Nervous System

1. Composed of sensory neurons and motor neurons

a. Act as independent communications pathways

b. Each monitors a different part of the body

2. Carries nerve impulses sent between CNS and rest of body

A. The brain and its four major parts

1. Cerebrum

a. Wrinkled outer layer

Organization of Human Nervous System

Central Nervous System

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b. Handles most sophisticated functions of brain (processes visual images, thinking, and planning)

2. Cerebellum-essential for coordination of movement

3. Brain stem-contains nerves that control vital life processes that are not consciously controlled (breathing, digestion, heart rate, etc.)

4. Hypothalamus

a. Body's center for emotions and instincts such as pleasure, pain, hunger, and thirst

b. Maintains body's temperature and water balance

B. Spinal cord-cable of nerve tissue that extends from brain stem down the back

1. Nerve impulses from body and brain run up and down it

2. Important component in making reflexes occur

3. Surrounded and protected by backbone

A. Sensory neurons

1. Carry nerve impulses from sense organs and receptors to CNS

2. Also referred to as afferent neurons

B. Motor neurons

1. Carry nerve impulses from CNS to muscles and glands

2. Also referred to as efferent neurons

"There are many different kinds of sensory receptors in your body. For example, your eyes, which are considered as sense organs, contain receptors called rods and cones. I would like all of you to take a few minutes to think about the various places these receptors are located throughout your body.”

Assign students roles to be different parts of the central nervous system. Clear a large area and have each student stand in the correct place for their part.

Peripheral Nervous System

Student Activities:

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Parts needed:

Wrap Up:

Brain - top of the classroom

Nerves - runners from the fingers and toes to the spinal column

Fingers

Toes

Spinal cord - runner from the nerves to the head

Explain how the central nervous system works. Then simplify it so the students so that they can demonstrate it: normally the nerve sends the information to the spinal cord, the spinal cord receives the information and sends it to the brain, the brain makes a decision and gives the information to the spinal cord, the spinal cord sends the information back to the nerves.

However, in an emergency, the nerves send the information to the spinal cord. It recognizes the danger and makes an instant decision. The nerves carry out that decision while the spinal cord sends the information to the brain. The brain then assesses the situation and agrees with the decision or makes a new one.

Give the students different scenarios to act out. Have the spinal cord person decide if he needs to make a decision or not. Scenarios could include:

touching a hot pan,

stepping on a tack on the carpet, and

something brushing against your leg in the dark.

For homework, have students write a story about their day as a spinal cord. Encourage them to talk about the decisions they had to make and if those decisions were right or wrong.

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WORKSHEET : 7A

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Answer the following questions.

The nervous system is made up of the brain, spinal cord and .

How many main parts does the brain have?

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two

three

Which part of the brain keeps your heartbeat and your breathing regular?

brain stem/medulla

cerebrum

cerebellum

Which part of the brain is in charge of balance and coordinating all the muscles?

brain stem/medulla

cerebrum

cerebellum

Which part of the brain is in charge if you are riding your bike?

Which part of the brain controls thinking, moving and sensing?

brain stem/medulla

cerebrum

cerebellum

The spinal cord connects the to the body's nerves.

Which part of the brain is in control when you read a book or play a game?

brain stem/medulla

cerebrum

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Which part of the brain is in control when you are reading your favorite book?

The medulla and the work all of the time, even when we don't know it.

Individual are in charge of seeing, hearing, smelling feeling, or touching something.

A quick action made by the body without the brain knowing about it is called a .

http://www.myschoolhouse.com/courses/O/1/34.as

(II) Label the diagram in the spaces provided with the correct name of each lobe of the brain.

Word Bank

Frontal Lobe

Occipital Lobe

Parietal Lobe

Temporal Lobe

Describe the functions of the:

Frontal Lobe:_________________________________________________________

Occipital Lobe:_______________________________________________________

Parietal Lobe:________________________________________________________

Temporal Lobe:________________________________________________________

http://faculty.washington.edu/chudler/fillobe.html

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DIVISIONS OF THE NERVOUS SYSTEM - A REVIEW

WORD BANK

Hemispheres hippocampus cerebellum brain

Amygdale cortex nerve thalamus

Sulcus Glia tract ganglia

Hypothalamus neurons gyrus spinal cord

corpus callosum nuclei cerebral cortex colliculi

________________________________________

Complete the following sentences using words from the Word Bank.

1. The Latin word meaning "bark" of a tree is used for the area of the brain called the________________.

2. The midbrain includes structures such as the superior and inferior __________ and red nucleus.

3. A structure important for movement and balance is the ______________.

4. The central nervous system is divided into two major parts: the ____________ and the __________.

5. In the central nervous system, collections of neurons are called _____________.

6. A bump or bulge on the cortex is called a __________and a groove is called a _______________.

7. One important function of the ________________________ is to control body temperature.

8. The brain contains about 100 billion ____________ and trillions of "support cells" called __________.

9. The limbic system is a group of structures that includes the __________________________, the hippocampus, mammillary bodies and cingulate gyrus.

10. In the Peripheral Nervous System, a collection of axons is called a ___________.

Instructions:

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11. The brain is divided into two halves called _______________________.

12. In the peripheral nervous system, collections of neurons are called ______________.

13. The _____________receives sensory information and relays this information to the __________________.

14. One part of the limbic system that is important for memory and learning is called the ___________________.

15. The right and left sides of the cerebral cortex are connected by a thick band of nerve fibers called the ____________________________.

16. In the central nervous system, collections of axons are called_______________.

http://faculty.washington.edu/chudler/fillobe.html

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ACTIVITY 7B: SIGNIFICANCE OF NERVOUS SYSTEM

Learning Outcome:


Problem:

Procedure:

The student will be able to understand significance of nervous system in human body.

3 chart papers folded, your writing instrument of choice, 3 pieces of poster board.

How does the Nervous system relate to a modern day security system? What does each part exactly relate to?

1. In-groups of two, you will design brochures and advertise what I call the nervous security system.

2. The key feature is to give an overall sense of the organization and function of nervous system. Tell how it acts as security system complete with sensors that tell the body there is something wrong. You may use drawings, computer graphics, photographs of actual organs, pictures from magazines, journals, or books to help in your advertisement of each system. Let your imagination run WILD!

3. You are to give your nervous security system a name.

4. Your brochure must include the following vocabulary: cell body, dendrites, neuron, axon, impulse, central nervous system, cerebellum, brain stem, spinal cord and peripheral nervous system.

5. Each group will orally present its brochure to the class.

http://www.teach-nology.com/worksheets/science/bio/lab8/


WORKSHEET 7B

1. What are the four main parts of a neuron?

Cell body, dendrites, axon, synaptic terminals

2. The site of contact between a synaptic terminal of a neuron and a target, such as a n o t h e r n e u r o n , a m u s c l e c e l l , o r a g l a n d , i s c a l l e d a ______synapse____________________.

3. What are the cells called that lie on each side of a synapse?

pre-synaptic cell and post-synaptic cell

4. The simplest type of nerve circuit is termed a ______reflex arc_________________.

5. What is the minimum number of neurons that can make up a "reflex arc", and what would these neurons be?

2, there must be at least one sensory neuron and at least one motor neuron

6. What are "interneurons"?

these are neurons within the CNS

7. Interneurons are constantly __active___. What does this active provide the context for?

for interpreting sensory input and directing an appropriate response

8. Ganglia and nuclei are collections of ______cell bodies of neurons______. How do they differ from one another?

Ganglia are found in the peripheral nervous system while nuclei are found within the brain.

9. What cells form the insulating sheaths around axons? Where are these cells found?

Schwann cells - outside the CNS, Oligodendrocytes - within the CNS

10. What two factors affect the speed at which an action potential travels down an axon?

The diameter of the axon, the larger the diameter the faster the action potentialThe presence of myelin around the axon, myelin insulates the axon and allows the action potential to travel by "salutatory conduction".

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Write the number of matching statements before the words given in first column

_____ afferent neurons 1) bundles of cell bodies outside of the CNS.

_____ autonomic nervous system 2) Potassium ions inside the plasma membrane and sodium ions are outside.

_____ axon 3) similar to the insulation of an electrical wire.

_____ central nervous system 4) largest part of the brain

_____ cerebellum 5) control of involuntary actions

_____ Cerebrum 6) transmit impulses to the cell body of a neuron

_____ Dendrites 7) comprised of the brain and spinal cord.

_____ Depolarization 8) allows the control of skeletal muscles.

_____ efferent neurons 9) similar to the body's "autopilot".

_____ Ganglion 10) indentations in the myelin

_____ Myelin 11) the membrane returns to its normal orpolarized state.

_____ nodes of Ranvier 12) sodium gates open and sodium ions rush into the neuron.

_____ Polarization 13) transmit impulses away from the CNS to an effector.

____ Polarization 13) transmit impulses away from the CNS to an effector.

_____ Repolarization 14) similar to a conductor in a electrical wire.

_____ somatic nervous system 15) a small gap between the presynaptic and postsynaptic membranes.

_____ Synapse 16) those that take impulses toward the CNS

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ACTIVITY 7C : REFLEX ACTION

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Learning Outcomes:

Content:

Simple or Unconditioned or Natural Reflex

Types of Simple Reflex

Students should be able to:

Explain how a voluntary reflex works

Explain how an involuntary reflex works

Describe the pathway of reflexes from cause to behavior

When the stimulation of a receptor results in a spontaneous, involuntary reaction, it is called reflex action or simply reflex.

Reflexes are of two types:

Simple or unconditioned or natural reflex

Complex or conditioned reflex

In this type of reflex, the brain is not involved. The receptor is stimulated which is conducted to the spinal cord by the effector. The effector neuron from the spinal cord conducts a response to the muscle or the gland. This causes an immediate reaction. It does not involve any thinking or reasoning. It is a natural response and will occur even in new-born babies. For example, blinking of eyes when strong light falls on the eyes.

Simple reflex is also of two types. They are as follows:

In the first type, only the sensory and motor neurons of the spinal nerves are involved.

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Jerking of knee when tapped below the kneecap is an example.

In the second type, the interneuron present in the spinal cord is also involved.

The moving away of hand in response to pin-prick or heat is an example of this type.

In the above diagrams, it can be seen that the pathway of conduction is in the form of an arc. Thus, these pathways are also called the reflex arcs.

Complex or Conditioned Reflex

This type of reflex involves the brain but it is also as fast as the simple reflex. Salivation on smelling one's favourite food is an example of conditional reflex. The individual recognises the smell and based on a previous experience, the response (salivation) occurs. The recognition of the previous experience involves the association centres of the brain. A series of experiments were conducted by Ivan Pavlov, a Russian biologist which demonstrated conditioned reflex. He found that when a bell was rung every time a dog was given food, the dog showed salivation only at the sound of the bell. The ringing of the bell is called the conditioned stimulus. The dog had, thus, 'learnt' to associate the sound of the bell to food and this made it salivate at the sound of the bell. It can be represented as follows:

Know Something

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Conditioning is the basis for learning. Learning to cycle or swim can be called a conditional response.

Materials, Equipment, Set-up -

4 rulers

neurological pathways poster

one whiteboard/chalkboard

Student Activity

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enough calculators for each student

data collection handout

(Enquiry Based )

Engagement (2 minutes)

While introducing the teaching team, drop a book or make some other loud noise unexpectedly

What just happened?

How did you react? What kind of behaviors did you see?

Why does the body react that way?

Where did you learn to do that?

Do other animals do the same thing?

There are 2 different kinds of reflexes: voluntary and involuntary

Involuntary reactions are the ones you just experienced, ones you can't really control. They go through the nerves without going to your brain.

Voluntary reflexes are ones that you have control over. The signal goes through the brain to be processed.

Both take very different paths through the circulatory system.

Exploration (8 minutes)

Students will attempt to calculate their voluntary reaction time using a ruler. In pairs the students will, one at a time, have their partner hold a ruler by the highest number end just above their fingers which are held in a pinching position. The fingers should not be touching the ruler. Without notice, the partner drops the ruler and the student's goal is to grab the ruler as quickly as possible. Students will do multiple trials and collect data on an Excel spreadsheet. After averaging that data, reaction times will be discovered using an existing. Each individual can graph their own reaction time as well on a piece of paper to see if/where they plateau.

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Explanation ( 5 min)

First ask students what they discovered, and why they thought it happened?

Using an illustration, explain the pathway of the reflex again.

Ask students what the difference is between what they just did, and what the doctor does to test their reflexes at the office.

Discuss the benefit of involuntary reflexes and why people react to a sudden loud noise the way they do.

Are your reflexes faster or slower if:

You know when the ruler is going to be dropped?

You aren't paying attention?

An object is hot?

You are scared? If faster, why?

Evaluation (3 min)

Draw the two different paths that reflexes take, both voluntary and involuntary.

Name three types of voluntary reflexes, and three types of involuntary reflexes.

How are we similar to animals you see outside when it comes to reflexes?

Elaboration (2 min)

What is the relationship between reflexes and age? Or gender? Allow the students to collect data from the teaching team and compare it to their results.

If we did 100 trials instead of 10 would the results be any different? Why?

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Try the experiment again with your non-dominant hand. Is your reaction time slower, faster or the same? Does it plateau at the same place?

A-Sensory Neuron B-Motor Neuron

http://academic.kellogg.cc.mi.us/herbrandsonc/bio201

http://mooreslore.corante.com/archives/images/axon.GIF

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ACTIVITY 7D: SYNAPSE

Learning Outcomes:

Student Activity 2

Conent :

At the end of this activity, students should be able to:

-explain that Nerve cells communicate with each other at a junction called a synapse

-structure and function of a synapse

- define a neurotransmitter.

Audio video Student Activity 1: How Neurotransmission Works

Nervous System-1.docx

http://science.education.nih.gov/supplements/nih2/addiction/activities/lesson2_neurotransmission.htm

The brain has one hundred billion neurons, more or less. They connect in a huge network exchanging billions of signals per second with one another and with your body. Neurons relay signals via the synapse, the tiny space between nerve cells. When a synapse occurs, neurotransmitters flow from one neuron to the next. A neurotransmitter is a chemical that relays the signal.

Neurons firing, synapses connecting, that's what the brain's all about. Nanobots are intercepting the neurotransmitters that make the synapse work. (Note: Show students synapse diagram on Lesson Handout.) Dr. Eric Chudler from the University of Washington explains the neurotransmission process this way: "Communication of information between neurons is accomplished by movement of chemicals across a small gap called the synapse. Chemicals, called neurotransmitters, are released from one neuron at the presynaptic nerve terminal. Neurotransmitters then cross the synapse where they may be accepted by the next neuron at a specialized site called a receptor. The action that follows activation of a receptor site may be either depolarization (an excitatory postsynaptic potential) or hyperpolarization (an inhibitory postsynaptic potential). A depolarization makes it MORE likely that an action potential will fire; a hyperpolarization makes it LESS likely that an action potential will fire.”

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Learning Outcomes:

Neurons convey information using electrical and chemical signals.

A Role Play

The students assume the role of sports reporters. They observe the role-playing activity, read the informational writing, complete the game-diagram activity, and play the Neuro Defender game. At the end of the lesson, students write a sports report for the local newspaper. A metaphor for the process of transmitting information from one cell to another can be found in our athletic games. For example, it is much like the game of football or soccer, where a team tries to score points by passing the ball to one of its members. The neurotransmitter is like the quarterback throwing the pass to the wide receiver or the forward on a soccer team passing the ball to a wing. The pass itself is like the synapse, where an idea or message is taken from one side to the other. In the Neuro Defender game, the Nanobots are the opposing team that tries to intercept the ball and stop the pass from the quarterback to the wide receiver or from the forward to the wing.

Role Play a Football Game Diagram

Copy and give each student the attached activity Diagram #1, The "Pass", to demonstrate the similarities between a football or soccer pass and the neurotransmission process in the brain. Review the diagram with the students. Divide the class into opposing teams. Assign a quarterback and a wide receiver from one team. Ask the quarterback to throw a football to the wide receiver. The people on the opposing team will try to intercept it.

Copy and give each student the activity Diagram #2, The Neurotransmission Process in the Brain (no labels), to demonstrate the process of neurotransmission.

Ask the students to work in small groups of 3 or 4 to label the diagram. Diagram #3, The Neurotransmission Process in the Brain (master with labels) is included for you to use as a guide. This activity will serve as a content vocabulary study and a way to transfer the student's prior knowledge of how a pass is used in a football game, which is similar to how neurotransmission works in the brain.

Play the Neuro-Defender Game:

NeuroDefender Game Description

Nerve impulses are releasing neurotransmitters to help send messages to Agent NM7's body so she can regain her balance in order to cross a dangerous chasm. These

Student Activity: 1 -

Student Activity: 2 -

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neurotransmitters are being launched into the synaptic cleft at nerve-ending terminals, where a neuron's axon meets another neuron's dendrite. However, one particular synaptic cleft has become a dangerous place for neurotransmitters. This synaptic cleft is filled with nasty Nanobots, sent to robotize Agent NM7's brain and stop the neurotransmitters from reaching their correct receptors. It's up to you to help guide the neurotransmitters safely to their final destinations.

You have a limited amount of time to find each neurotransmitter's correct receptor before the body takes over and sends in its own big guys, Acetylcholinestrase, to destroy the well-meaning neurotransmitters. Once the player has successfully docked all three neurotransmitters, the synapse fires. Agent NM7 regains her balance and coordination and is able to cross the chasm.

This is the movie screen script.

Use this to help build the students' background knowledge prior to playing the game.

Movie Script: Intro to NeuroDefender

Yeah, like I was saying, your brain's got a hundred billion neurons more or less. They connect in a huge network exchanging billions of signals per second with one another and with your body. The neuron's a busy little nerve cell. Neurons relay signals via the synapse, the tiny space between to neurons. When a synapse occurs, neurotransmitters flow from one neuron to the next. A neurotransmitter is a chemical that relays the signal.

Neurons firing, synapses connecting, that's what the brain's all about. Here's a synapse that's got all it going on. But the other synapse has issues, and guess who's to blame. Nanobots are intercepting the neurotransmitters that make the synapse work. Get in there and stop them!

Movie Script: NeuroDender Finale

You did it! The synapse is working again. Agent NM7 will

make it across the chasm!

Write a sports report that describes the process.

Ask students to assume the role of a sports reporter. They should play the Neuromatrix game again and refer to their Diagram #2, The Neurotransmission Process in the Brain.

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Student Activity:5

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They can write a sports report about the neurotransmission process and include their own drawings to illustrate the process. For example, students can write a "play-by-play" coverage report or a summary of the game. Ask students to share their sports reports with the class or post them online on a class web site.

http://www.morphonix.com/docs/NeuroDefenders%20Lesson%20final2.pdf

Copyright © 2003 Nelson Chapter 9 How Nerve Signals Maintain Homeostasis

Label the diagram using the terms given below

presynaptic membrane postsynaptic membrane synaptic vesicle

neurotransmitter substance synaptic cleft receptor sites mitochondria

Number these events in the correct order.

1………… (a) An action potential is stimulated at the postsynaptic membrane and impulse travels down dendrite.

2 …………. (b) An enzyme cleaves the neurotransmitter substance and clears out the synaptic cleft.

3 …………. (c) Impulse reaches synapse from the axon.

WORKSHEET : 7S

Events of a Synaptic Transmission

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4 …………. (d) Impulse stimulates synaptic vesicles to move to presynaptic membrane.

5…………..(e) Neurotransmitter substance diffuses across the cleft.

6 …………. (f) Neurotransmitter substance fits into receptor sites on postsynaptic membrane.

7………......(g) Synaptic vesicles dump neurotransmitter substance into synaptic cleft.

http://chatt.hdsb.ca/~duncand/FOV1-000D8CF8/FOV1-000E9548/FOV1-000E954E/synapse.pdf

The student will be able to

Turn your classroom into a giant synapse as students act out communication at the neural level by behaving as pre-synaptic vesicles, neurotransmitters, postsynaptic receptors, secondary messengers and re-uptake transporters. Neurotransmitters and receptors interact via "lock-and key" puzzle pieces

Nerve cells communicate with each other at a junction called a synapse. When stimulated by an action potential, a neuron releases neurotransmitters into the synapse.

Receptors on the outside of the receiving cell (post synaptic cell) fi t synapticneurotransmitters similar to a "lock and key". Once neurotransmitters "lock" into the appropriate receptor, a secondary messenger is released in the receiving cell.

After neurotransmitters have done their job, they are released from the receptors and sent back through the cell through re-uptake transmitters. In the sending cell,neurotransmitters are packaged in vesicles.

(2) 15-foot sections of rope or masking tape

Classroom set of Job Assignment Tags (included)

String for Job Assignment Tags

Neurotransmitter/Receptor complex puzzle pieces (included)

ACTIVITY 7E : CONCEPT OF ACTION POTENTIAL

2

2

2

2

Learning Outcomes :

Materials Required

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CD or tape player, music

Basic neuron structure, neurons communicate using action potentials and chemicals called neurotransmitters

Nerve cells communicate with each other at a junction called a synapse.

When stimulated by an action potential, a neuron releases neurotransmitters into the synapse.

Receptors on the outside of the receiving cell (post synaptic cell) fi t synaptic neurotransmitters similar to a "lock and key". Once neurotransmitters "lock" into the appropriate receptor, a secondary messenger is released in the receiving cell.

After neurotransmitters have done their job, they are released from the receptors and sent back through the cell through re-uptake transmitters.

In the sending cell, neurotransmitters are packaged in vesicles.

1. Place masking tape or rope on the fl oor of your classroom, hallway, basketball court etc… to represent pre- and postsynaptic membranes. The membranes need to be arranged in an area large enough for several of your students to move back and forth from one side to the other comfortably.

2. Review the structure of a neuron, including: cell body, nucleus, axon, synapse and dendrites. Focus student's attention on the terminal end of the axon and the synapse. Show Overhead A. Explain that this activity will focus on this area and it's role in communication between neurons.

3. Place Overhead B on top of Overhead A to show how student roles correlate with structures in the synapse. Assign students their roles and give the students the appropriate Job Assignment tag prepared

4. Position the students around the membranes you've created on the fl oor accordingly. Give the students who are dopamine neurotransmitters a dopamine neurotransmitter puzzle half

5. Give students who are dopamine receptors a dopamine receptor puzzle ha

2

2

Content:

Teacher Action

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6. The two students who are serotonin receptors should also be given a serotonin receptor puzzle half There will be no complementary puzzle half for these. Print Job Assignment tags, cut out, attach string to hang around the neck Print Neurotransmitter and Receptor puzzle halves cut out and laminate.

Tip: Adjust the number of Job Assignments and puzzle halves to accommodate the number of students in your classroom. We recommend starting with the neurotransmitters, receptors and uptake transporters.

For a group of 23

1Print Job Assignment tags, cut out, attach

string to hang around the neck (Teacher

Resource Pages 5-6)

Print Neurotransmitter and Receptor puzzle

halves (Teacher Resource Pages 1-4), cut

out and laminate.

Tip: Adjust the number of Job Assignments and

puzzle halves to accommodate the number of

students in your classroom. We recommend

starting with the neurotransmitters, receptors and

uptake transporters.

http://gslc.genetics.utah.edu/teachers

http://teach.genetics.utah.edu/content/addiction/JumpinTheGap.pdfhttp://teach.genetics.utah.edu/content/addiction/JumpinTheGap.pdf

1. http://www.bioedonline.org/resources/files/4_BLCh_MessageInNeuron.pdf All cells have a membrane potential; however, only certain cells such as __neurons__________ and ____muscle cells_________ have the ability to generate large changes in their membrane potential. These cells are called _____excitable_________________________.

Preparation

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2. What types of ion channels are present in the cell membrane? How are these channels opened?

ungated channels and gated channels, ungated channels are always open while gated channels are opened either by chemicals or by a threshold voltage

3. What are the two different types of "graded potentials"?

hyperpolarization and depolarization

4. Define each type of "graded potential". Tell which ion channel is involved in each type of "graded potential".

hyperpolarization - a change in membrane potential so that the membrane potential becomes more negative compared to resting membrane potential, K+ ion channel

depolarization - a change in membrane potential so that the membrane potential becomes less negative compared to resting membrane potential, Na+ ion channel

5. Why are these voltage changes called "graded potentials"?

because the amount of hyperpolarization or depolarization depends upon the strength of the stimulus

6. If a sufficiently strong stimulus causes depolarization to reach "threshold potential" it triggers a different type of response called an _____action potential________.

View Solution

Label the Brain Anatomy Diagram

Read the definitions below, then label the brain anatomy diagram.

Cerebellum - the part of the brain below the back of the cerebrum. It regulates balance, posture, movement, and muscle coordination.

Corpus Callosum - a large bundle of nerve fibers that connect the left and right cerebral hemispheres. In the lateral section, it looks a bit like a "C" on its side.

Parietal Lobe of the Cerebrum - the middle lobe of each cerebral hemisphere between the frontal and occipital lobes; it contains important sensory centers (located at the upper rear of the head).

Pituitary Gland - a gland attached to the base of the brain (located between the Pons and the Corpus Callosum) that secretes hormones.

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Copyright ©2001-2010 EnchantedLearning.com ------ How to cite a web page

Frontal Lobe of the Cerebrum - the top, front regions of each of the cerebral hemispheres. They are used for reasoning, emotions, judgment, and voluntary movement.

Medulla Oblongata - the lowest section of the brainstem (at the top end of the spinal cord); it controls automatic functions including heartbeat, breathing, etc.

Occipital Lobe of the Cerebrum - the region at the back of each cerebral hemisphere that contains the centers of vision and reading ability (located at the back of the head).

Pons - the part of the brainstem that joins the hemispheres of the cerebellum and connects the cerebrum with the cerebellum. It is located just above the Medulla Oblongata.

Spinal Cord - a thick bundle of nerve fibers that runs from the base of the brain to the hip area, running through the spine (vertebrae).

Temporal Lobe of the Cerebrum - the region at the lower side of each cerebral hemisphere; contains centers of hearing and memory (located at the sides of the head).

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ACTIVITY 8A : ROLE OF HORMONES

Activity:


Learning Outcome:

Students will be able to relate the changes in their body and emotionally with the hormones.

Introduce the unit with this story. "You are cycling in a neighborhood park. Out of the corner of your eye you see a large, vicious looking dog looking at you. He is growling, barking and showing his teeth. Suddenly he breaks free from his leash and comes straight toward you. Your heart begins to pound, your hands get sweaty and your muscles tighten up. You grab your cycle and race to your parent's car. As you slam the door, the dog jumps up against the window. You are safe now but your heart is still pounding."

What do you think you would feel?

The students will write their experiences and feelings on a sheet of paper.

The teacher will read out a few and then introduce the topic- Hormones

The teacher will then introduce the term Hormones and Endocrine glands.

Teacher: In this unit we will learn how the endocrine system can help with a quick response to danger and how it slowly turns you from a child to a pre-adolescent to an adult.

The teacher will pose following questions:

Who feels tired and sleepy in the first part of the school day?

Who feels sleepy in the afternoons?

Take a poll and put results on board.

Teacher: The rhythm of wakefulness is controlled by hormones.

The endocrine system works like and automatic thermostat. When the building gets hot, the air conditioner comes on: when it is cold , the heater comes on. When our bodies need fuel, hormones are released to stimulate feelings of hunger. When we are

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threatened, a hormone prepares our muscles to be ready for action. We are going to find out what hormones are produced and secreted by the various endocrine glands as well as the location of the various glands.

Although we rarely think about them, the glands of the endocrine system and the hormones they release influence almost every cell, organ, and function of our bodies. The endocrine system is instrumental in regulating mood, growth and development, tissue function, and metabolism, as well as sexual function and reproductive processes.

Endocrine System: This system helps to regulate all the body's functions. It controls the rate we grow, our feelings of hunger, our body temperature, how much fluid we have in our bodies and much more. The endocrine system could be called the rhythm section of our lives. These glands secrete hormones that are responsible for how fast and large we grow, how awake we are, how happy we feel and more. Some hormones help us mature into adult men and women.

The students will be shown a picture of location of endocrine glands in the body.


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WORKSHEET : 8A

Questions: Write True or False against each of the following statements:

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ACTIVITY 8B : EXOCRINE AND ENDOCRINE GLANDS

Learning outcome:

The students would be able to differentiate between exocrine and endocrine glands.

The teacher may explain:

Gland is a group of cells that produces and secretes, or gives off, chemicals. A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body.

Some types of glands release their secretions in specific areas. For instance, exocrine glands, such as the sweat and salivary glands, release secretions in the skin or inside the mouth. Endocrine glands, on the other hand, release more than 20 major hormones directly into the bloodstream where they can be transported to cells in other parts of the body.

The major glands that make up the human endocrine system include the:

hypothalamus

pituitary gland

thyroid

parathyroids

adrenal glands

pineal body

reproductive glands (which include the ovaries and testes)

Observe the types of glands shown in the picture. Compare their secretions and their effect.

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WORKSHEET : 8B

1. Identify the endocrine and exocrine glands shown in the picture shown below. Give their secretions and their target organs.

2. Explain the process shown below.

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ACTIVITY 8C : FEEDBACK MECHANISM OF HORMONE ACTION

2

2

2

Student Activity 1:

Learning Outcome :

Students would be able to understand the feedback mechanism of hormonal action

negative feedback The stopping of the synthesis of an enzyme by the accumulation of the products of the enzyme-mediated reaction.

negative feedback control Occurs when information produced by the feedback reverses the direction of the response; regulates the secretion of most hormones.

negative feedback loop is A biochemical pathway where the products of the reaction inhibit production of the enzyme that controlled their formation.

An example of a simple negative feedback loop

Students will prepare a skit to show the regulation of Glucose in the body

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WORKSHEET : 8C

1. Explain the negative feedback control shown in the schematic diagram shown below:

2.

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ACTIVITY 9: REGULATION OF PHOTOPERIODISM

Learning Outcome:

Exploration

The students would be able to explain the involvement in regulation of Photoperiodism.

Content: Students track photoperiod (daylight hours) over time and predict how daylight will change during different seasons. This helps build their understanding that ever-changing daylight is the driving force for migrations and all other seasonal changes.

ideas on a chart that they can revisit and revise at the end of this learning experience.

Challenge the class to discover how the amount of daylight changes throughout the school year.

1. Ask students to hypothesize whether the amount of daylight (called photoperiod) will increase or decrease between fall and winter, winter and spring, and spring and summer. Have them explain the thinking behind their responses.

2. Set up a class chart, or have students use individual charts, to write down the sunrise and sunset times for your location each day, each week, or only on the equinoxes and winter solstice.

3. Once students have gathered the data, they should calculate the photoperiod (hours of daylight) - and high or average temperatures, if they have them - for each date; Finally, they can graph their data.

PHOTOPERIODISM: The day length during which light is available to the plants is called Photoperiod.

The effect of day length (photoperiod) on the developmental processes of plant (like germination of seeds & flowering) is called PHOTOPERIODISM

Plants respond to photoperiodic stimulus which the help of a pigment called Phytochrome. It is a blue green pigment which responds to light.

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e.g.

1. Photoperiodism is involved in germination of seeds.

2. Flowering of tobacco plants is a photoperiodic response

Phytochrome functions as a photoreceptor in many plant responses to light and photoperiod

A pigment named phytochrome helps plants measure the length of darkness in a photoperiod.

Phytochrome Receptors

Photoperiodism takes place in specialized pigment materials called phytochrome receptors. Phytochrome receptors act as light sensors that integrate with a plant's biological clock and provide a means for a plant to adapt to its lighting conditions. These receptors also absorb available light energy and use it to activate the genes involved in seed development and flowering. In effect, phytochrome pigments can measure the time periods that elapse through successive days and nights.

Skit: Prepare a skit to show how phytochromes affect photoperiodism.

2

Student Activity:

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WORKSHEET : 9

1. Which substance(s) produced in one part of a plant affect(s) another part?

A. oxygen and nitrogen

B. hormones

C. herbicides

D. enzymes

2. Which hormones influence the shedding of leaves?

A. gibberellin and auxin

B. phytochrome and gibberellin

C. auxin and ethylene

D. cytokinin and phytochrome

3. Roots growing with gravity and stems growing against gravity are examples of

A. photoperiodism.

B. thigmotropism.

C. gravitropism.

D. phototropism.

4. Plant hormones are produced in

A. the buds of flowers.

B. roots.

C. old leaves.

D. flowers in full bloom.

5. What is a pigment that regulates the changes in activity that prepare plants for winter?

A. phytochrome

B. ethylene

C. meristem

D. cytokinin

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6. Hormones that stimulate cell elongation and are produced in the rapidly growing region near the tip of the plant's root or stem are called

A. auxins.

B. ethylenes.

C. gibberellins.

D. cytokinins.

7. The growth of plant seedlings is usually

A. thigmotropic and gravitropic.

B. phototropic and gravitropic.

C. phototropic and influenced by ethylene.

D. gravitropic and influenced by ethylene

8. The response of a plant to changes in the length of day or night is called

A. abscission.

B. photosynthesis.

C. photoperiodism.

D. thigmotropism.

9. The responses of plants to external stimuli are called

A. gibberellins.

B. tropisms.

C. cytokinins.

D. auxins

10. Powerful synthetic auxins are sometimes used as

A. fertilizers.

B. insecticides.

C. herbicides.

D. fruit ripeners.

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ACTIVITY 10 : HUMAN BRAIN

2

2

2

Learning objectives:

Content:

Students will be able to

Describe the major regions of human brain and list their functions

The average human brain weighs about 1,400 grams (3 lb). When the brain is removed from the skull, it looks a bit like a large pinkish-gray walnut. The brain can be divided down the middle lengthwise into two halves called the cerebral hemispheres. Each hemisphere of the cerebral cortex is divided into four lobes by various sulci and gyri. The sulci (or fissures) are the grooves and the gyri are the "bumps" that can be seen on the surface of the brain. The folding of the cerebral cortex produced by these bumps and grooves increases the amount of cerebral cortex that can fit in the skull. (In fact, the total surface area of the cerebral cortex is about 324 square inches - about the size of a full page of newspaper!). Although most people have the same patterns of gyri and sulci on the cerebral cortex, no two brains are exactly a like.

FRONTAL LOBE

Located in front of the central sulcus.

Concerned with reasoning, planning, parts of speech and movement (motor cortex), emotions, and problem-solving.

Find out more about the frontal lobe with the story of an unlucky worker in 1848 who survived an iron rod that went through his head!! Read about Mr. Gage and the

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frontal lobe in a GREAT multimedia slide show. If you are interested in a book about Phineas Gage, try Phineas Gage: A Gruesome but True Story About Brain Science by John Fleischman (Boston: Houghton Mifflin Co., 2002).

PARIETAL LOBE

Located behind the central sulcus.

Concerned with perception of stimuli related to touch, pressure, temperature and pain.

TEMPORAL LOBE

Located below the lateral fissure.

Concerned with perception and recognition of auditory stimuli (hearing) and memory (hippocampus).

OCCIPITAL LOBE

Located at the back of the brain, behind the parietal lobe and temporal lobe.

http://www.eduref.org/Virtual/Lessons/Science/Anatomy/ANA0202.html

Identify and locate parts of the brain and the actions they control by acting out the following functions: Students will write something they remember, solve a math problem and make a decision, then point to the top of their head to the cerebrum, as well as on the brain diagram worksheet.

Students will cough, sneeze, and feel their pulse, and point behind their ear to the medulla, and illustration. Balance on one foot, rub their head and pat their stomach. Follow by pointing to the lower-back portion of their head to the cerebellum, and on the diagram. Names of parts are said aloud as they point to them. Repeat.

2

2

2

2

2

Student activity-1.

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Student activity-2.

Student activity-3.

Create a nervous system model by getting into pairs, trace each other's body on butcher-block paper, then glue twisted strands of yarn on their body tracing for the spinal cord. Strands of yarn will be glued on extending from the s p i n a l c o r d -outward through the body as the nerves. The brain will be glued on cotton balls.

Act out the parts of the nervous system and what each one's function is in a skit. One student will be the brain, acting as the "control center". This student will send messages to students acting as five senses and other body parts on note cards, and receive information on note cards from those body parts and senses. Students acting as the spinal cord will pass along the messages, and the rest of the students will run messages and incoming information along the nerves.

A diagram will be taped on the floor of the nervous systems and the i r locat ions . http://www.franklincollege.edu/pwp/dbrown/UnitInquiries.pdf

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WORKSHEET : 10

Here is a short review about the 4 lobes of the brain. Take a look at this figure and then answer the questions. The numbers on the figure correspond to the number of the question.

The lobe of the brain most important for vision ...

Occipital Temporal Parietal

2. The lobe of the brain most important for hearing ...

Occipital Temporal Frontal

3. The lobe of the brain most important for touch ...

Occipital Parietal Frontal

4. The lobe of the brain most important for reasoning and planning...

Frontal Temporal Parietal

5. The largest lobe of the human brain is the...

Temporal Occipital Frontal

6. The human brain weighs about ...

1 pound 3 pounds 5 pounds

Read the definitions below, then label the brain anatomy diagram.

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www.enchantedlearning.com/subjects/.../brain/Classroom.shtml - Cached - Similar

Cerebellum - the part of the brain below the back of the cerebrum. It regulates balance, posture, movement, and muscle coordination.

Corpus Callosum - a large bundle of nerve fibers that connect the left and right cerebral hemispheres. In the lateral section, it looks a bit like a "C" on its side.

Frontal Lobe of the Cerebrum - the top, front regions of each of the cerebral hemispheres. They are used for reasoning, emotions, judgment, and voluntary movement.

Medulla Oblongata - the lowest section of the brainstem (at the top end of the spinal cord); it controls automatic functions including heartbeat, breathing, etc.

Occipital Lobe of the Cerebrum - the region at the back of each cerebral hemisphere that contains the centers of vision and reading ability (located at the back of the head).

Parietal Lobe of the Cerebrum - the middle lobe of each cerebral hemisphere between the frontal and occipital lobes; it contains important sensory centers (located at the upper rear of the head).

Pituitary Gland - a gland attached to the base of the brain (located between the Pons and the Corpus Callosum) that secretes hormones.

Pons - the part of the brainstem that joins the hemispheres of the cerebellum and connects the cerebrum with the cerebellum. It is located just above the Medulla Oblongata.

Spinal Cord - a thick bundle of nerve fibers that runs from the base of the brain to the hip area, running through the spine (vertebrae).

Temporal Lobe of the Cerebrum - the region at the lower side of each cerebral hemisphere; contains centers of hearing and memory (located at the sides of the head).

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ACTIVITY 11 : EEG AS AN IMPORTANT TOOL

2

Activity 12 : Structure and Function of The Human Eye

2

2

2

Learning outcome:

Learning Outcome:

Content:


Understand EEG as an important tool to detect Brain diseases(lesions)

http://www.youtube.com/watch?v=KtfiQ5mdybU

EEG Brain waves game


identify the parts of the eye and

explain the visual system of the brain.

Recognise sense organs as gateways for receiving information from the environment

AQUEOUS HUMOR:

clear, watery fluid circulating in both chambers of eye, associated with the chamber outside the lens.

CHOROID:

a thin, highly vascular membrane on which the retina rests; between the retina and sclera.

CILIARY BODY:

part of the eye that joins the iris with the anterior portion of the choroid.

CONES:

photoreceptor cells in the retina used under conditions of bright illumination; are color coded (red, green, and blue); mediate fine detail vision; contain photopigments with low sensitivity to light (i.e., cannot see colors in dim illumination).

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CONJUNCTIVA:

thin layer of mucous membrane lining the inner surface of each eyelid,moves over the eyeball as a protective cover.

CORNEA:

convex, transparent coating of the eye (made up of collagen-rich epithelial cells) which covers the pupil and iris, consisting of five layers allowing light to pass through to the lens; it is dense, nonvascular, uniform in thickness, and projects like a dome beyond the sclera; the degree of corneal curvature varies in different individuals and in the same person at different ages; curvature is more pronounced in youth than in advanced age.

EYELID:

movable fold of skin over the eye with lashes and glands along its margin

FOVEA (FOVEA CENTRALIS):

area at the center of the retina where cone cells are concentrated and there are no rod cells; "blind spot.”

IRIS:

circular, opaque, contractile diaphragm controlling the diameter of the pupil; divides the space between the lens and the cornea into an anterior and a posterior chamber; the colored part of the eye surface containing dark pigment cells variously arranged in different people to produce different colored irises; pigment absent in albinos.

INTRAOCULAR PRESSURE:

pressure of the eye, regulated by resistance to the flow of aqueous humor through a fine sieve-like trabecular meshwork (eye's drainage system); the older the person, the more likely it is that the trabecular meshwork becomes hardened and obstructed, preventing the normal flow of aqueous humor from passing out at the proper rate and causing an increase in the intraocular pressure (IOP).

© 2001 UTHSCSA "Positively Aging®" a trade mark of the University of Texas Health Science Center at San Antonio 6-2 UNIT-6

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LENS (CRYSTALLINE LENS):

a transparent, colorless, firm structure of the eye, enclosed in a capsule, located between the iris and the vitreous humor; refracts light to focus images onto the retina at the back of the eye; in old age the lens becomes flattened, more dense, slightly opaque, and amber-tinted.

MACULA LUTEA:

an oval yellow spot at the center of the retina, near the optic nerve; around fovea (blind spot); region of retina richest in photoreceptors; contains a pit, fovea centralis, and has no blood vessels; central vision occurs when an image is focused directly on the fovea centralis.

MUSCLES OF THE EYE:

CILIARY MUSCLE - controls the diameter of the pupil (how much light passes through the lens); ciliary muscle adjusts the shape of the lens (and hence focal length) by varying the tension of the muscle

OPTIC NERVES:

either of a pair of second cranial nerves; transmits visual data from retina to brain.

PUPIL:

the "hole" or circular opening in the iris through which light passes to the lens and the retina; located slightly to the nasal side of the center of the iris; lies behind the anterior chamber of the eye and the cornea and in front of the lens; diameter changes with contraction and relaxation of the muscular fibers of the iris as the eye responds to changes in light, emotional states and other kinds of stimulation.

RETINA:

a ten-layered, delicate, membrane of light-sensitive nervous tissue at the back of the eye; contains photoreceptors (rods and cones) and the neurons which transmit visual impulses from sensory cells through the optic nerve to the brain; is in contact with the choroid, the inner surface with the vitreous body; is soft, semitransparent, and contains rhodopsin, which gives it a purple tint; becomes clouded and opaque if exposed to direct sunlight.

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RODS:

one of the photoreceptor cells in the retina; contain photopigments which are very sensitive to low light levels; located mainly around the periphery of the retina; do not code for color.

SCLERA:

tough, opaque membrane of the eyebulb which maintains the size and form of the bulb and attaches to muscles that move the bulb; the whites of the eyes.

VITREOUS HUMOR:

transparent, semigelatinous fluid in the chamber filling the cavity behind the crystalline lens of the eye.

Sources: WWW.familyconnect.org

http://teachhealthk-12.uthscsa.edu/curriculum/vision-hearing/vision01a-anatomy.asp

paper, pencils, colored pencils, or crayons.

Select two to three activities per classroom session.

Materials Needed:

Classroom Activities:

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Student Activity 1:






Allow 15 minutes for students to work in pairs. Allow 5 minutes for

classroom discussion.

Divide the classroom into pairs. Ask students to examine their partner's eyes and to draw a large picture of one eye, putting in as many details as they can. Have them notice the color and texture of the eye, and use crayons to lightly color the drawing. Students can compare the similarities and differences in the color, shape, and texture of each other's eyes. Circulate through the room during this activity and stimulate discussion.

Allow 15-20 minutes.

Distribute Handout: The Anatomy of the Eye. Ask students to fill in the parts of the eye. Review and discuss the definitions with the students.

Allow 10 minutes.

Pupil dilation : Divide the classroom into pairs. Ask students to observe their partner's pupils automatically get larger and smaller as the classroom lights are turned off for 10 seconds, then turned back on.

Explain that the black spot in the middle of the iris-the pupil-is really a hole through which light enters the eye. The iris is a muscle that expands and contracts to control the amount of light that enters the eye. In bright light, the iris expands and the pupil shrinks so that only a little of the available light enters the eye.

Allow 15 minutes.

Classroom or Take Home Activity: Distribute Handout: Optical Illusions.

Review the handout with the class.

Allow 15-20 minutes.

Classroom or Take Home Activity: Distribute Handout: Scramble and Word Search. Review the handout with the class.

Allow 20 minutes.

Distribute Handout: The Visual System. Review with the students.

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WORKSHEETS : 12

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Fill in parts of the EYE

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http://www.nei.nih.gov/education/VISIONschool/schintro/VISIONSchoolProgram.pdf

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Shiksha Kendra, 2, Community Centre, Preet Vihar, Delhi-110 092 India

CENTRAL BOARD OF SECONDARY EDUCATION

biology science unit-2 - nims · pdf fileresult of phyto-hormones. plants respond to stimuli...

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