FA-03ACTIVITY- 01

Class: 10th ‘A’Subject : Control & Coordination in

Plants & Animals

SRI SATHYA SAI SARASWATHI BOYS HIGH SCHOOL

MARADEVANAHALLI2016-2017

Name: RAKESH MRoll No:10A24

Submitted To: Nandish Sir

CONTROL AND

COORDINATION

Plants respond to stimulus by two ways either by growth movements such as changes shown by growing plants or by some chemical changes such as in case of Mimosa pudica. It is very quick movements.

Immediate response such as in Mimosa the information is transferred by electrochemical changes from cell to cell and the movement occurs by change in cell size by osmosis.

In normal condition the cell remains turgid and maintains normal posture but as a stimulus received the cells stars exosmosis as a result water comes out of the cells and shrinks in size.

Coordination In Plants

In some plants movements occurs by growth such as increase in size, in tendrils which are sensitive to touch.

Tendril when comes in contact with some object the part which is away grow rapidly and coils around the object.

Bending of plant stem towards the light is also a growth movement. These movements are slow.

Growth Movement

On the basis of stimulus the movements are of various types:

Phototropism: light is stimulus and plants move towards or away from the light. Stem is positively phototropic.

Geotropism: gravity is stimulus and plants move towards or away from the light. Root is positively geotropic.

Hydrotropism: water is stimulus and plants move towards or away from the light. Root is positively hydrotropic.

Chemotropism: chemical is stimulus. Pollen tube shows chemotropism while entering the ovule.

The nervous system show insufficiency as it does not associated with each cell and it require a resting period before setting a new impulse. So there is a need of having a system in which cell secretes some chemicals which can be detected by other cell even transmitted also.

HormonesThese are chemical messengers which are secreted by endocrine glands and released directly into the blood from where they can reach to the target organ and show their effect.

Chemical Coordination

Auxins: it helps in elongation of cells.

Cytokinins: it promotes cell division.

Gibberellins: it helps in growth of plant in length.

Abscisic Acid: it inhibits growth and it also induces Dormancy (period in which no growth occurs during unfavorable conditions)

Plant Hormones

Organism is in direct contact with its environment, so any changes in its surroundings have an influence on its body. To maintain the balance between the environmental factors and body functions there is a need of such controlling and coordinating system that works for the welfare of the organism.

Need Of Control And Coordination In Animals:

In animals this control and coordination is carried out by Nervous and muscular system. Human nervous system consists of two parts:

Central nervous system: It consists of Brain and Spinal Cord.

Peripheral Nervous System: It consists of cranial and Spinal nerves. 12 pairs of cranial nerves and 30 pairs of spinal nerves.

NERVOUS SYSTEM:

It is the main part of the Nervous system consisting of two main Organs:Brain and Spinal cord. These parts are the main centre for receiving, interpreting and generating response for any stimulus.

CENTRAL NERVOUS SYSTEM:

It is the most complex organ in the human body. It is divided into three main parts: 1. Forebrain, 2. Midbrain 3. Hindbrain.

It is the centre of performing all type of actions either voluntary (actions that are controlled by organism) or involuntary in nature (actions that are not controlled by organism).

It perform the functions same as that of a central processing unit (CPU) in computer.

BRAIN

It is the front and largest part of the brain. It consists of Olfactory lobes, diencephalon and Cerebrum.

FUNCTIONS:It is the main thinking part of the brain. It has separate area for receiving sensory impulses It also transmits motor impulses to the muscles to

show response. It has centre for hearing, hunger, smell, sight,

intelligence, memory, learning, vision, mood and emotions.

Hypothalamus and pituitary glands secretes variety of Hormones.

FORE BRAIN

It is the back part of brain and consists of medulla, pons varoli and cerebellum.

FUNCTIONS:It controls the involuntary actions along with

mid brain.Blood pressure, Heart beat, sneezing, salivation

and vomiting are controlled by medulla.Cerebellum is responsible for equilibrium,

precision of voluntary actions, maintaining posture and balance of the body.

HIND BRAIN

Our central nervous system is properly protected to prevent any injury.

Brain is placed inside a bony box known as Cranium, Inside which the brain is surrounded by a fluid to protect from shock.

Spinal cord is also placed in the vertebral column.

Protective Structures Of Brain:

It is the longest cell found in human body may reach up to a length of 1 meter.

Nerve cell is divided into three parts i.e. Cell body, Dendrites and Axon.

Cell body is rounded part having a nucleus and other cell organelles. Cell body bears short thread like structure known as dendrites which receives the stimulus.

Axon is a long process which carries information to one neuron to another neuron.

A very small gap is present in between two neurons, this gap is known as Synapse.

NERVE CELL:

Functioning: The stimulus is received by the dendritic tips of a nerve cell

and carried in form of an electrical impulse. Impulse travels from dendrites to cell body and then

through the axon at its end. Here it set up a chemical impulse by releasing some

chemicals known as Neurotransmitters in the synapse. These chemicals pass through the synapse and reach to

dendrites of other neuron to transfer the information again in electrical form.

When synapse occurs between a neuron and muscle cell then it is known as Neuromuscular Junction.

Acetylcholine is the neurotransmitter present in the synapse.

It is a nerve mediated spontaneous, automatic involuntary response to a stimulus without the will of the organism. It is discovered by Marshall Hall in 1833.

Example:- If we accidentally touch a hot plate our

hand moves backward instantly without thinking of the matter happening.

It occurs by the involvement of Spinal cord so it happens very quickly as the receptors and effectors are in direct contact with each other in spinal cord.

Reflex Action:

It is the path followed by the reflex action to show a response.

Receptors Sensory Nerves Spinal Cord Motor Nerves Effectors

Reflex Arc:

Conduction of nerve impulse from sensory receptors to brain and then to effectors to show the response is carried out by nerves. But actually the response is shown by the muscles or gland cells. Muscles cells are able to change their shape because of the presence of some contractile proteins which results in movement of muscles. Myosin and Actin are the proteins which unable the muscle to move.

Action Of Nervous Tissue:

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