Biology – The Nature of ScienceBiology – The Nature of Science

How do we use science to study How do we use science to study life?life?

What tools do we use?What tools do we use?

How do we share our findings?How do we share our findings?

What characteristics do all living What characteristics do all living things have?things have?

Chapter 1 Key terms• Biology• Organism• Organization• Reproduction• Species• Growth• Development• Environment• Stimulus• Response• Homeostasis• Energy • Adaptation• Evolution

• Scientific methods

• Hypothesis• Experiment• Control• Independent

variable• Safety symbol• Data• Theory

InferenceRead the following story and then indicate your response to each of the statements Read the following story and then indicate your response to each of the statements

printed below the story.printed below the story.A business man had just turned off the lights in the store when a man A business man had just turned off the lights in the store when a man

appeared and demanded money. The owner opened the cash register. The appeared and demanded money. The owner opened the cash register. The contents of the cash register were scooped up and the man sped away. A contents of the cash register were scooped up and the man sped away. A member of the police force was notified promptly.member of the police force was notified promptly.

Indicate your response to each of the following statements, by checking "True" if Indicate your response to each of the following statements, by checking "True" if you believe it to be true, "False" if you believe it to be false, and "???" if you you believe it to be true, "False" if you believe it to be false, and "???" if you cannot determine whether it is true or false.cannot determine whether it is true or false.

True False ???True False ???1.1. _____ A man appeared after the owner had turned off the store lights._____ A man appeared after the owner had turned off the store lights.2.2. _____ A man received cash._____ A man received cash.3.3. _____ The robber was a man._____ The robber was a man.4.4. _____ The man who opened the cash register was the owner._____ The man who opened the cash register was the owner.5.5. _____ The store owner scooped up the contents of the cash register._____ The store owner scooped up the contents of the cash register.6.6. _____ Someone opened a cash register._____ Someone opened a cash register.7.7. _____ The cash register was empty when the owner opened it._____ The cash register was empty when the owner opened it.8.8. _____ After the man scooped up the contents of the cash register, he _____ After the man scooped up the contents of the cash register, he

ran away.ran away. You!

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True

False

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DirectionsDirectionsTo unlock the secrets of Science, ALL that is needed is curiosity, a well-ordered or logical mind, To unlock the secrets of Science, ALL that is needed is curiosity, a well-ordered or logical mind,

patience, patience, ABILITY TO FOLLOW DIRECTIONSABILITY TO FOLLOW DIRECTIONS, a respect for safety while dealing with , a respect for safety while dealing with equipment and chemicals, and (last, but not least) a knowledge of elementary mathematics.equipment and chemicals, and (last, but not least) a knowledge of elementary mathematics.

FOLLOWING DIRECTIONS EXERCISEFOLLOWING DIRECTIONS EXERCISE

The answer to each question is The answer to each question is yeyes. If you cannot answer yes, go back and redo the previous step s. If you cannot answer yes, go back and redo the previous step or steps.or steps.

1.1. Obtain a square sheet of paper.Obtain a square sheet of paper.

2.2. Fold the paper diagonally.Fold the paper diagonally.

3.3. Position the triangle on the desk with the long side facing you.Position the triangle on the desk with the long side facing you.

4.4. From left t o right, 1abe1 the corners A, From left t o right, 1abe1 the corners A, B, C.B, C.

5.5. Fold point C along edge AB, so that the top edge of the fold is parallel to the base of the original Fold point C along edge AB, so that the top edge of the fold is parallel to the base of the original triangle. Do you see three triangles?triangle. Do you see three triangles?

6.6. From left to right, label the corners of the triangle you just made D, E, F.From left to right, label the corners of the triangle you just made D, E, F.

7.7. Fold A to point F. Do you see four triangles? If not, Go back two steps.Fold A to point F. Do you see four triangles? If not, Go back two steps.

8.8. Fold a single layer of side B down in front as far as it will go.Fold a single layer of side B down in front as far as it will go.

9.9. Turn facedown the side with E showing.Turn facedown the side with E showing.

10.10. Fold the flap, which is now showing, as far down as it w ill go.Fold the flap, which is now showing, as far down as it w ill go.

11.11. Fill the CUP with water. Is it watertight? If it leaks, get a new piece of paper and go back to Fill the CUP with water. Is it watertight? If it leaks, get a new piece of paper and go back to step 1.step 1.

Designing an Experiment

State the Problem

Form a Hypothesis

Set Up a Controlled Experiment

Record Results

Analyze Results

Draw a Conclusion

Publish Results

Scientific MethodScientific Method

Scientific Method Activity

Scientific Method and the Holy Grail

Smithers thinks that a special juice will Smithers thinks that a special juice will increase the productivity of workers. He increase the productivity of workers. He creates two groups of 50 workers each and creates two groups of 50 workers each and assigns each group the same task (in this assigns each group the same task (in this case, they're supposed to staple a set of case, they're supposed to staple a set of papers). Group A is given the special juice to papers). Group A is given the special juice to drink while they work. Group B is not given drink while they work. Group B is not given the special juice. After an hour, Smithers the special juice. After an hour, Smithers counts how many stacks of papers each counts how many stacks of papers each group has made. Group A made 1,587 group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.stacks, Group B made 2,113 stacks.

1.1. Control GroupControl Group

2.2. Independent Variable (Independent Variable (manipulated variablemanipulated variable))

3.3. Dependent Variable (Dependent Variable (responding variableresponding variable))

4.4. What should Smithers' conclusion be?What should Smithers' conclusion be?

5.5. How could this experiment be improved?How could this experiment be improved?

Homer notices that his shower is covered in a Homer notices that his shower is covered in a strange green slime. His friend Barney tells strange green slime. His friend Barney tells him that coconut juice will get rid of the green him that coconut juice will get rid of the green slime. Homer decides to check this this out slime. Homer decides to check this this out by spraying half of the shower with coconut by spraying half of the shower with coconut juice. He sprays the other half of the shower juice. He sprays the other half of the shower with water. After 3 days of "treatment" there with water. After 3 days of "treatment" there is no change in the appearance of the green is no change in the appearance of the green slime on either side of the shower. slime on either side of the shower.

6.6. What was the initial observation?What was the initial observation?

7.7. Identify the Control GroupIdentify the Control Group

8.8. Independent VariableIndependent Variable

9.9. Dependent VariableDependent Variable

10.10. What should Homer's conclusion be?What should Homer's conclusion be?

Bart believes that mice exposed to microwaves Bart believes that mice exposed to microwaves will become extra strong (maybe he's been will become extra strong (maybe he's been reading too much Radioactive Man). He decides reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been mice to another 10 mice that had not been exposed. His test consisted of a heavy block of exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-push the block away. 7 out of 10 of the non-microwaved mice were able to do the same.microwaved mice were able to do the same. Identify the-Identify the-

11. Control Group11. Control Group

12. Independent Variable12. Independent Variable

13. Dependent Variable13. Dependent Variable

14. What should Bart's conclusion be?14. What should Bart's conclusion be?

15. How could Bart's experiment be improved?15. How could Bart's experiment be improved?

Krusty was told that a certain itching powder was Krusty was told that a certain itching powder was the newest best thing on the market, it even claims the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it product, he buys the itching powder and compares it to his usual product. One test subject (A) is to his usual product. One test subject (A) is sprinkled with the original itching powder, and sprinkled with the original itching powder, and another test subject (B) was sprinkled with the another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to having itches for 30 minutes. Subject B reported to have itches for 45 minutes. have itches for 45 minutes.

Identify the-Identify the-16. Control Group16. Control Group

17. Independent Variable17. Independent Variable

18. Dependent Variable18. Dependent Variable

19. Explain whether the data supports the advertisements claims about 19. Explain whether the data supports the advertisements claims about its product.its product.

Lisa is working on a science project. Her task is to Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the growth". Her family is willing to volunteer for the experiment. experiment.

20. Describe how Lisa would perform this experiment. Identify the 20. Describe how Lisa would perform this experiment. Identify the control group, and the independent and dependent variables in your control group, and the independent and dependent variables in your description. description.

Measurement  SI unit Definition

 Length Meter (m) The standard SI unit to measure length is the meter (m).

100 cm = 1 meter

10 mm = 1 centimeter

1000 M = 1 kilometer

Weight Newton (N) Weight is a measure of the gravitational force on an object.

Mass Gram (g) Mass is the amount of matter in an object.

Measurement• Most scientific studies and experiments use a standard system of metric units

called Le Système International d’Unités, or SI for short. SI is a modern version of the metric system based on a decimal system that uses the number 10 as the base unit.

Area m2

(length x width)

Area is the amount of surface included within a set of boundaries and is expressed in square units of length, such as square meters (m2).

Volume m3

(length x width x depth)

The amount of space occupied by an object is the object’s volume.

SI measurements for liquid volumes are usually made in milliliters (mL) or liters (L).

Density density = mass / volume Density is a measure of the amount of matter that occupies a given space.

Temperature In science, temperature is often measured on the Celsius (C) scale.

In SI, temperature is measured on the Kelvin (K) scale.

Temperature is a measure of the average vibrations of the particles that make up a material.

Temperature is measured in degrees with a thermometer.

Time The SI unit of time is the second (s).

Time is the interval between two events and is usually measured with a watch or clock.

MeasurementsMeasurements

Analyzing and Presenting DataAnalyzing and Presenting DataY

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X Axis – Independent X Axis – Independent Manipulated Manipulated VariableVariable

All graphs should include the All graphs should include the following:following:

TitleTitleUnitsUnitsLabelsLabelsEven spacingEven spacing

The Line GraphThe Line Graph - -This kind of graph This kind of graph shows the relationship between two shows the relationship between two kinds of data in which the independent kinds of data in which the independent variable is continuous. variable is continuous.

The Bar GraphThe Bar Graph -Bar graphs are used -Bar graphs are used when there is no continuity from one when there is no continuity from one piece of data to the next.piece of data to the next.

Making graphs

Communicating ResultsCommunicating Results

•One important goal of science is to make results available to others.One important goal of science is to make results available to others.

•Communicating scientific data and results allows others to learn of new Communicating scientific data and results allows others to learn of new discoveries, to possibly verify what has been reported, and to conduct new discoveries, to possibly verify what has been reported, and to conduct new experiments using the information.experiments using the information.

Candle Activity:Candle Activity:

Identify phenomenaIdentify phenomena

Develop a testable hypothesisDevelop a testable hypothesis

Design an experiment to test you Design an experiment to test you hypothesishypothesis

Models

• A scientific model is an idea, a system, or a mathematical A scientific model is an idea, a system, or a mathematical expression that is similar to the idea being explained.expression that is similar to the idea being explained.

– While a model might not have all of the components of a given idea, it should be a fairly accurate representation.

– Models can change when more data is gathered.

Introduction to Environmental Modeling

InputsInputs Flows (throughputs)Flows (throughputs)

Stores (storage areas)Stores (storage areas) OutputsOutputs

Scientists project the behavior of complex systems by developing a model of its inputs, throughputs (flows), and outputs of matter, energy, and information

Theories and LawsTheories and Laws

• A scientific A scientific theorytheory is an explanation based on many observations is an explanation based on many observations during repeated experiments.during repeated experiments.

– A scientific theory is valid only if it is consistent with A scientific theory is valid only if it is consistent with observations, makes predictions that can be tested, and is the observations, makes predictions that can be tested, and is the simplest explanation of observations. simplest explanation of observations.

– A theory can be changed or modified with the discovery of new A theory can be changed or modified with the discovery of new data.data.

• A scientific A scientific lawlaw is a basic fact that describes the behavior of a natural is a basic fact that describes the behavior of a natural

phenomenon.phenomenon.

A scientific law can be thought of as a “rule of nature,” even though the A scientific law can be thought of as a “rule of nature,” even though the cause of the law may not be known. cause of the law may not be known. The events described by a law are observed to be the same every time. The events described by a law are observed to be the same every time. Theories are often used to explain scientific laws.Theories are often used to explain scientific laws.

Science vs. PseudoscienceScience: Science: “Extraordinary “Extraordinary claims require claims require extraordinary extraordinary proof”proof”

Make a list of Make a list of differences differences between science between science and and pseudosciencepseudoscience

Applying Scientific Methods

Insects751,000

Protists57,700

Plants248,400

Prokaryotes4,800

Fungi69,000

Other animals281,000

Known species1,412,000

What are the Characteristics of Life?What are the Characteristics of Life?

All things living have the All things living have the following specific propertiesfollowing specific properties::

Cellular organization Cellular organization

Metabolism Metabolism

Growth and DevelopmentGrowth and Development

Respond to EnvironmentRespond to Environment

HomeostasisHomeostasis

Reproduction Reproduction

HeredityHeredity

EvolveEvolve

Biotic – living components of an ecosystem

Abiotic – Nonliving component of an ecosystem

Characteristics of Living Things Examples:

Living things are made up of units called cells.

Many microorganisms consist of only a single cell. Animals and trees are multicellular.

Living things reproduce. Maple trees reproduce sexually. A hydra can reproduce asexually by budding.

Living things are based on a universal genetic code. Heredity

Flies produce flies. Dogs produce dogs. Seeds from maple trees produce maple trees.

Living things grow and develop. Flies begin life as eggs, then become maggots, and then become adult flies.

Living things obtain and use materials and energy. Metabolism

Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat.

Living things respond to their environment

Leaves and stems of plants grow toward light.

Living things maintain a stable internal environment. Homeostasis

Despite changes in the temperature of the environment, a robin maintains a constant body temperature.

Taken as a group, living things change over time. Evolve

Plants that live in the desert survive because they have become adapted to the conditions of the desert.

Its Alive 1 Its Alive 2

Is it Alive?