The goal of science is to investigate and understand nature, to explain events in

nature, and to use those explanations to make useful

predictions.

I. What is science?A. Science is an organized way of using

evidence to learn about the natural world.

B. (It also means the body of knowledge that exists about the natural world)

– Science only deals with what can be tested. It does not make value judgments.

Genetically Modified Food• Breyer's Ice Cream• Budweiser beer• Campbell's Soup• Diet Coke • Enfamil Infant

Formula • Friskies & Purina• Healthy Choice • Green Giant• Kelloggs• Nestle• Kraft

III.The Significance of Biology as a Science

1. The world’s food supply2. Environmental factors that might be harmful3. Maintaining the environment4. Medicines and medical treatment5. Maintaining good health6. Providing energy to power automobiles, homes,

and industry

• An understanding of science and the scientific approach is essential to making intelligent decisions.

Designing an Experiment using the Steps of the Scientific Method: a series of steps scientists use to answer or solve a problem

1.State the Problem

2. Form a Hypothesis

3. Set Up a Controlled Experiment

4. Record Results

5. Analyze Results

6. Draw a Conclusion

7. Share Results

8. REPEAT!!

IV. The Scientific Method is even used to

solve everyday problems.

You may not realize it, but you probably use the scientific method many times throughout your

day.

Tim and Moby’s Experiment.

Why did Tim and Moby want to set up an experiment?

What were they testing?

Throughout the experiment, what did each plant have or receive that was exactly the same?

Throughout the experiment, what did each plant receive that was varied or different?

Why couldn’t Moby and Tim have set up their experiment like this to test if watering a plant too much would cause it to die?

A Flower A Cactus A Tree A weed

Plant A Plant B Plant C Plant DNever watered Watered everyday Watered 3 times/week Watered once/week

A Controlled Experiment

A. Only tests one variable at a time (Variable= factor in an experiment)

B. Control– Sometimes called constants. What the scientist keeps constant

• Most experiments have a control group. This group does not receive the manipulated variable. The control group is used as a standard of comparison.

Control Group- A group in the experiment that is kept in its natural state

• What were Tim and Moby’s controls? Same type of plant, the same type of pot, the same amount of soil, the same amount of sunlight

A Controlled Experiment

C. Manipulated Variable- Sometimes called the independent variable. What the scientist deliberately changes (Should only have one – this is usually what is being tested)

• What was Tim and Moby’s manipulated variable?

The amount of water

A Controlled Experiment

D. Responding Variable – sometimes called the dependent variable. changes in response to the manipulated variable

• What was Tim and Moby’s responding variable? Plant Growth

OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.

HYPOTHESIS: PROCEDURE

Controlled Variables:

Manipulated Variables:

Uncovered jars Covered jars

Several days pass

Maggots appear No maggots appearResponding Variable:

Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

Section 1-2

Redi’s Experiment on Spontaneous Generation

Go to Section:

Flies produce maggots.

jars, type of meat,location, temperature,time

gauze covering thatkeeps flies away from meat

whether maggots appear

CONCLUSION:

E. Hypothesis: a possible explanation or answer to a scientific question

• Experiments are performed to test a hypothesis

F. Theory: a hypothesis that has been supported by many experiments and a lot of evidence.