Download Biology Unit 1 Review Guide ANSWERS

BIOLOGY – Mr. Channell
NAME: _______________________
Biology Unit 1 Review Guide ANSWERS
Complete on a separate sheet of paper if needed.
1. Define “biology.”
Study of life in the biosphere.
2. Explain the process of experimental design (the steps a scientist follows).
Make an observation, ask a question, form a hypothesis, test and collect data,
form a conclusion.
3. Explain the difference between independent and dependent variables.
The independent variable is what you change in the experiment, while the
dependent variable is what changes as a result of you’ve changed.
4. Explain the importance of control groups and variables in experimental design.
A control group gives you a means to compare against the experimental
group, which has undergone the change you’ve made (the independent
variable). Control variables make sure that everything between the control
group and the experimental group are the same except for the one variable
that you’ve changed (again, this change you make is called the independent
variable.)
5. Why did the theory of biogenesis replace the theory of spontaneous generation?
Spontaneous generation claimed that life could spring from non-living
things, which we found to be untrue as time went on and research methods
improved. We now know that life can only come from pre-existing life.
6. Identify the smallest unit of life.
The cell.
7. List the life processes and briefly describe each.
Reproduction – producing offspring
Growth – getting to adult size
Excretion – getting rid of waste
Respiration – getting energy from food
Sensitivity – reacting to stimuli
Movement – moving parts of the body
Nutrition – finding food to stay alive
OTHERS – Evolution (change over time) and Internal organization (organ
systems)
8. Define the word "organic" as used in class.
Matter that comes from once-living things. Always contains the element
Carbon.
9. Describe (or draw and label) the structure of an atom.
10. Explain how carbon atoms form bonds and identify the types of structures
formed when many carbons bond together.
Carbon atoms have 4 valence (outermost) electrons, allowing them to create
4 bonds with other atoms to create chemical compounds. Quite often, carbon
bonds to other carbon atoms to form straight chains, branched chains, or
rings.
11. List the main elements found in living things.
C (Carbon), H (Hydrogen), O (Oxygen), N (Nitrogen).
12. List the elements that make up the structure of each of the following: proteins,
lipids, and carbohydrates.
Proteins – C, H, O, N
Lipids – C, H, O, N, some P (Phosphorus)
Carbohydrates – C, H, O
13. State the uses of each of the following types of molecules in the body: proteins,
lipids, carbohydrates.
Proteins – repairs muscle…aids in cell functions as enzymes, hormones,
antibodies, etc
Lipids – over ½ the body’s energy comes from lipids…can be stored as long
term energy
Carbohydrates – provide immediate energy…can’t be stored long term
14. Give 2+ examples of foods that would be a good source of each of the following:
protein, lipid, carbohydrate.
Protein – meat, fish, dairy, eggs
Lipids – nuts, eggs, fish, oils
Carbohydrates – breads, pastas, fruits, rice, vegetables
15. Compare and contrast mono-, di-, and polysaccharides.
Monosaccharides – simple carbs made of only 1 sugar unit
Disaccharides – simple carbs made of 2 sugar units
Polysaccharides – complex carbs made of 3+ sugar units
16. Explain how a dehydration synthesis (condensation) reaction works.
Water is removed to link monomers to form polymers.
17. Explain how a hydrolysis reaction works.
Water is used to break a larger molecule apart. Also releases ATP (energy).
18. Draw the pH scale and label the location of acids, bases and neutral. Also
distinguish between strong and weak acids and bases.
19. Explain the function and importance of enzymes in the body. Include the effects
of pH and temperature in your explanation.
Enzymes are molecules that affect the rates of chemical reactions in your
body by acting as catalysts. This means they lower the amount of energy
needed to “kick start” a reaction in your body (activation energy). Too
high/low temperature or pH can affect their effectiveness, or prevent them
from working at all.
20. Write two or three sentences that explain the relationship between the following
terms: enzyme, catalyst, activation energy, substrate.
An enzyme works as a catalyst to lower the amount of activation energy
needed to start a chemical reaction in the body. Substrates, which are
substances an enzyme works on to lower activation energy, fit with enzymes
through a “lock and key” method, where the proper substrates fit perfectly
together with the proper enzyme.
21. Explain the relationship between elements and compounds.
Elements are the simplest form of matter, while compounds are multiple
elements that have been chemically bonded together.
22. Explain the importance of ATP.
ATP (adenosine triphosphate) is a chemical compound that is high in energy
and allows us to do everything we do.
23. Why can lipids store large amounts of energy?
Lipids are particularly long chains of carbons bonded together. ATP
(energy) is stored in every bond in the chain.