The Science of The Science of BiologyBiology

Chapter 1.1 - 1.3

Vocabulary( define these terms in your spiral notebook in your own words)

1. science2. biology3. observation4. data5. qualitative6. quantitative7. inference8. hypothesis9. scientific method10. control group11. scientific theory

12. scientific law13. spontaneous

generation14. cell 15.15. sexual reproductionsexual reproduction16.16. asexual reproductionasexual reproduction17.17. metabolismmetabolism18.18. stimulusstimulus19.19. homeostasishomeostasis20.20. evolutionevolution

I. What is Science?A. Science vs. Legend

1. humans have always sought to explain the events of the world

2. legend or myth = an explanation of the natural world that cannot be observed with the 5 sensesa. Ex: thunder is the sound of an angry god

3. belief = confidence in the existence of anything that cannot be tested by science

4. science = process of investigating and understanding the natural worlda. organized b. based on evidence from your 5 sensesc. used to make predictions using evidence

5. biology = the study of life

B. How Science Works1. observation = gathering information in

a careful and orderly way using your five senses

2. data = facts collecteda. quantitative = uses numbers to describe

the evidence1. Ex: How many mice are in the area?

1. qualitative = more descriptive, cannot be easily measured1. Ex: What color are the fish’s spots?

3. Inference & Hypothesisa. Inference = logical interpretation based on

prior knowledge and experience1) Ex: By examining samples of pond water taken in

different places, you can infer the make up of organisms throughout the entire pond.

b. Hypothesis = a proposed explanation based on observationsa. Ex: I hypothesize that the light intensity of a glow

stick will increase as temperature increases.b. Hypotheses are often proven wrong by the data of

the experimentc. Often there are competing hypotheses, ex:

unknown disease1) disease “X” spreads through physical contact2) disease “X” spreads through the air, food, or

water3) disease “X” spreads from insect bites

4. Science is a processa. Science is an ongoing process, not a set of

absolute truthsb. Our understanding improves as new tests

and new data is collected every day!c. Good scientists are skeptical, questioning

existing ideas and new hypotheses

What process do we use to learn about science and biology?

5 Steps of Scientific Method Movie

QuickTime™ and aSorenson Video 3 decompressorare needed to see this picture.

C. The Scientific Method

1. State the question or problem(Come up with a problem with your

partner)

2. Gather background information on the problem

Why?3. Form a hypothesis

4. Design an experiment to test your hypothesisa. RULES TO FOLLOW:

1) Have a control group (i.e. the group that is not exposed to experimental variable)

2) Test only one variable3) Use as many subjects as possible (30 is

minimum)b. Manipulated variable (independent) –

deliberately changedc. Responding variable (dependent) –

observed change in response to manipulated variable

(Design an experiment to test your hypothesis)

Setting Up a Controlled Experiment Movie

5. Record and analyze data6. Form a conclusion (3 parts)

a. Address your hypothesis -- use your data to support or reject your hypothesis referring to data from the experiment

b. Error analysisc. Suggestions for future

experiment1) Specific changes to eliminate

errors2) Future experiments

7. Repeat experiment Why?

Designing an Experiment

State the Problem or Question

Form a Hypothesis

Set Up a Controlled Experiment

Record Results

Analyze Results

Draw a Conclusion

DRAW now

Publish Results

Background Information

D. Scientific Theories & LawsIn every day language, “theory” means a hunch or opinion not

based on fact.1. scientific theory = an explanation of nature supported by many

facts gathered over time (describes why something works)a. Some theories are so well established that no new evidence is likely to

alter them

b. ex: theory of plate tectonics*** leave space for drawing on next slide

2. law = how nature behaves under certain conditions (usually mathematical)

a. ex: law of gravity = objects with mass accelerate toward each other

DRAWDRAWnownow

E. Historical Experiments

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

HYPOTHESIS: Flies produce maggots.PROCEDURE

Controlled Variables:jars, type of meat,location, temperature,time

Variable:gauze covering thatkeeps flies away from meat

Uncovered jars Covered jars

Several days pass

Maggots appear No maggots appear

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

1. Redi’s Experiment on Spontaneous Generation

2. Pasteur’s Test of Spontaneous Generation

Pasteur’s experiment showed that all living things come from other living things

Broth is boiled. Broth is free ofmicroorganismsfor a year.

Curved neckis removed.

Broth is teeming with microorganisms

II. Characteristics of Life

What makes something an organism (living thing)?

If I were to place an unknown object on your desk what criteria would you use to determine whether or not it was a living organism?

A. Made Up of Cells1. cell = smallest unit of an

organism, a collection of chemicals and living matter surrounded by a barrier

2. all organisms are made of cells

3. organisms are either multicellular (made of many cells) or unicellular (made of a single cell)

B. Reproduce1. All organisms can produce

offspring by sexual or asexual reproduction

a. sexual reproduction = 2 individuals exchange genetic information, new individual is a combination of both parents

b. asexual reproduction = 1 individual produces a genetically identical offspring

C. Based on Genetic Code1. An organism’s traits

are determined by its genetic code, its DNA

D. Grow and Develop1. an organism grows and develops over a

period of time

2. can be a simple change in size to a complete change in form

E. Must Consume Energy1. All organisms need energy

to continue life

2. Metabolism = the combination of breaking down food and building the chemicals necessary for life functions

F. Respond to the Environment1. Living things remain alive by responding

to the environment.

2. Stimulus = a signal to which an organism responds (internal and external)

a. Ex: Plants bend to get the maximum amount of light possible and animals run from threats (like your shoe hovering over a roach).

G. Maintain an Internal Balance

1. Homeostasis = a living organism’s need to maintain a relatively stable set of internal conditions

a. Ex: body temperature in warm blooded organisms or water levels in all organisms

2. no homeostasis = death

H. Evolution1. organisms change

over timea. Over 100,000s or

millions of years, these changes can be huge!

Characteristics of Living Things Examples

Are made up of units called cells

Reproduce

Are based on a genetic code

Grow and develop

Use materials and energy

Respond to their environment

Maintain a stable internal balance

Evolve (group changes over time)

Unicellular: Multicellular:Sexual: Asexual:Flies produce:Maple tree seeds produce:Life cycle of a fly:

Plants:Animals:

Plants: Animals:

If you’re in the cold air of snowy mountains, your internal body temp is ____________.

Plant:Animal:

I. Characteristics of Life Table(DRAW - fill in your table with examples)