Download Questions (Please answer on a separate sheet)

Questions (Please answer on a separate sheet)
Chapter 1:
1. How does an observation differ from an inference?
Observation: information perceived using the senses. Inference: assumptions/conclusions
made from observation
2. How can a graph of data be more informative than a table of the same data?
Graphs are more visual and can help you to predict future trends.
3. List and describe each of the biological levels of organization.
Molecule, Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem,
Biosphere (see text for descriptions).
4. A young animal normally grows larger no matter what food it eats. Suggest an experiment that
would show whether one type of food was better than another at helping an animal to grow
faster.
IV: type of food
DV: rate of growth
CV: amount of food; amount of exercise
Chapter 2:
5. Explain the properties of cohesion and adhesion. Give an example of each property.
Cohesion: attraction of like substances (really, a property of water); consider surface
tensionan insect walking on water
Adhesion: attraction of unlike substances; consider the meniscus created by water as it settles
in a graduated cylinder
6. What are ions and isotopes?
Ions are atoms/molecules with a different number of electrons than protons. They have either
a positive or negative charge. Isotopes are atoms with different numbers of neutrons and
protons. They have different masses than their unchanged counterparts.
7. Describe two factors that influence enzyme activity and explain how this occurs
Enzyme activity can be slowed, for example, by a decrease in temperature, which causes the
enzymes and substrates to move more slowly and collide with each other less frequently.
Another way is to have an environment that is too acidic or alkaline. This condition could
denature the enzyme, changing its shape so that the active (binding) site no longer matches
the substrate.
8. As part of the digestive process, the human stomach produces hydrochloric acid, HCl.
Sometimes excess acid causes discomfort. In such a case, a person might take an antacid such
as magnesium hydroxide, Mg(OH)2. Explain how this substance can reduce the amount of acid
in the stomach.
Magnesium hydroxide is a base as noted by the OH in its chemical symbol and the word
‘hydroxide’ in its name. Bases neutralize acids, so taking some Mg(OH)2 would help reduce the
acid in the stomach.
Chapter 7:
9. Describe the structure of a cell membrane. How does the cell membrane affect the contents of
the cell?
The cell membrane is composed of a phospholipid bilayer. It regulates what enters and exits
the cell.
10. What is meant by an isotonic solution? Do particles move across the membrane in an isotonic
solution?
Isotonic means “equal strength” or “equal concentration”. Even during equilibrium, particles
would move across the membrane. They would move back and forth across the membrane at
equal rates in order to maintain equilibrium.
11. Which organelle helps prevent damage to cells that are subjected to high osmotic pressure?
The cell wall is rigid and resistant to osmotic pressure. This makes it very difficult to burst.
12. What would happen to a sample of your red blood cells if they were placed into a hypotonic
solution? Explain your solution.
Hypotonic (low strength) refers to the solute concentration of a substance. If red blood cells
were placed in a hypotonic solution, it would mean that the concentration of water was higher
OUTSIDE of the cell compared to inside. Thus, water would diffuse into the cell and the cell
might burst.
Chapter 8:
13. Compare the amounts of energy stored by ATP and by glucose. Which compound is used by the
cell as an immediate source of energy?
Glucose stores nearly 90 times the energy of an ATP molecule. However, ATP is used by cells
for immediate energy.
14. How were Priestley’s and Ingenhousz’ discoveries about photosynthesis related?
Priestley expanded Ingenhousz’ experiment to determine that plants give off oxygen only in
the presence of light.
15. What are leaf stomata and what purpose do they serve for plants?
Leaf stomata are like pores in plant leaves. They are holes surrounded by guard cells and they
allow materials like CO2 and water in, while also allowing water to leave the plant.
16. Write a metaphor to explain the energy differences between ADP & ATP and also NADP + and
NADPH.
The four molecules listed can be compared to charged or depleted batteries. ADP and NADP +
are the depleted, low-energy forms and ATP and NADPH are their respective high-energy
forms.
Chapter 9:
17. How is glucose changed during glycolysis? What products are produced as a result of
glycolysis?
During glycolysis, glucose is converted into pyruvic acid. Glycolysis produces ATP and NADH in
addition to pyruvic acid.
18. What are the two pathways that might follow glycolysis? What factor determines which of the
pathways a cell might follow?
Glycolysis is followed by cellular respiration (Krebs cycle and Electron Transport Chain) in the
presence of oxygen. Glycolysis is followed by fermentation (lactic acid or alcoholic) in the
absence of oxygen.
19. What is the chemical equation for cellular respiration?
6O2 + C6H12O6  6CO2 + 6H2O + energy (ATP)
20. Certain types of bacteria thrive in conditions that lack oxygen. What does that fact indicate
about the way they obtain energy?
If the bacteria lack oxygen, they cannot carry out cellular respiration. This means that they
must obtain their energy via glycolysis and fermentation.