Biology EOC review
answers
Ch 1: scientific method
1.
2.
3.
4.
5.
A
D
D
B
C
6. C
7. D
8. C
9. A
10. D
11.
12.
13.
14.
15.
C
C
B
C
C
16.
17.
18.
19.
20.
D
B
D
D
B
21. A . State the problem (in question form)
B. Collect information about the problem
C. Form a hypothesis (a possible answer) ( must be
testable)
D. Design and conduct an experiment (use an
experimental group with a variable, and a control group
without the variable.)
E. Record observations and data
F. Check results; redo experiment as needed
G. Draw your conclusions (accept or reject hypothesis)
H. Communicate your results.
22. Hypothesis is a possible answer, or an educated guess.
Theory is a general statement supported by many
scientific observations and experiments, and
represents the most logical explanation of the evidence.
23. A research plan is necessary before testing a
hypothesis to ensure that there is only one
variable, and that there are valid controls.
24. A clear statement of a hypothesis is important
because it could lead to the answer of a
question.
25. A scientist can collect and organize data in
tables, charts, and graphs
26. The results of one experiment cannot become
a theory; a theory must be supported by
MANY experiments and observations.
27. B
28.
control group: solution with no salt
experimental group 1 5% salt
experimental group 2 10% salt
experimental group 3 15% salt
two conditions constant: water temperature,
number of shrimp, amount of solution in
containers
29. C (D)
30. C
31. -hypothesis: if we grow the plants in acidic
soil, they will be a different color.
-The control group will be grown in (normal)
slightly basic soil.
-Both the experimental and control groups
should be in the same amount of soil,
should receive the same amounts of
water and sunlight.
-one piece of evidence supporting my
hypothesis would be flowers that were
a color (not white)
32. Corn seedlings are only one type of plant, so to
make generalizations about plants, many types
should be studied.
33. It is important to include all steps of an experiment so
that other researchers can repeat it and verify the
results
34. A hypothesis should be changed whenever new,
conflicting information is found
35. Charles Darwin kept a journal so that he could keep
track of all details and data, as well as new ideas.
36. -Question: can seeds travel long distances in the ocean
and still able to grow?
-Hypothesis: If I soak seeds in salt water, and then
plant them, they will grow.
-Experiment: he soaked many different kinds of seeds,
for short and long periods of time, and then planted
them.
Chapter 2: Laboratory tools and
techniques
1. C
2.
3.
4.
5.
B
B
D
B
6.D
7.C
8.D
9.C
10.D
11.D
12.D
13.D
16.A (and B)
14.A
17.A
15.C (A) 18.A
19.D
20.B
21. C
22. C
23. A
24. D
25. A 10-ml graduated cylinder, should be read at
eye-level, to the bottom of the meniscus
26. Measurements are useful for accuracy so
reliable, valid, information can be obtained
and analyzed to draw conclusions.
27. Scientists use tools and instruments to
improve the accuracy of their observations.
28. A. Use a medicine dropper to place a drop of
water on the slide.
B. Use the medicine dropper to place the
specimen into the water on the slide.
C. Gently lower a coverslip, one edge down at
a 45-degree angle first
D. Add a drop of stain at one edge , and draw
it through with a piece of paper towel.
29. Similarities: both are used to magnify
images more than 250,000 times, and they
use electron beams and magnetic lenses.
Differences: the TEM passes beams
through a specimen. The SEM passes
beams over the surface.
30.
volume: liters
temperature: degrees Celsius
mass: kilograms
length: meters
31. (safety rules)
32. They could rub a piece of each food on a piece
of brown paper bag and look for grease.
33. Scientists have used electron microscopes to
see much smaller objects.
34. Both types of microscopes are used to magnify
small objects. Light microscopes can be used
to see living objects; electron microscopes can
be used to see much smaller objects, because
no light is involved.
35. Don’t bother.
Ch 3: Organic Molecules: from
Atoms to Cells
1.
2.
3.
4.
5.
6.
7.
B
D
B
A
D
B
C
8. D
9. B
10. A
11. A
12. C
13. A
14. A
15. B
16. B
17. B
18. A
19. B
20. D
21. B
22. To maintain high levels of organization
necessary to stay alive, organisms require
energy.
23. Carbon is of special importance to living things
because organic compounds are built on a
“skeleton” or framework of carbon atoms.
24. Four important functions of organic
compounds are: capturing and transforming
energy, building new structures, storing
materials, and repairing structures.
25. Athletes need lots of complex carbohydrates
during training to supply energy.
26. C
27. B
28. They have different amino acid sequences, and
different conformations.
29. C
30. Three important characteristics of proteins:
a. Made of subunits called amino acids
b. Main functions are to build new materials, transport
substances, send signals, provide defense, control
chemical and metabolic activities
c. Structure and function is determined by the
sequence of the amino acids, and the conformation
(shape) of the molecule.
31. The particular proteins in our body depend
upon our DNA, because the nucleotide
sequence determines those proteins.
32. Tissues are groups of cells, such as nervous
tissue that is made up of nerve cells or
neurons. Organs are made of tissues working
together, such as the brain which is made of
nervous, blood, and connective tissues.
33. Main levels of organization:
atoms, molecules, organic compounds,
organelles, cells, tissues, organs, organ
systems, organisms.
34. Evolution explains the problems with weight loss in
that a favorable adaptation would be the ability for a
person’s metabolism to slow down when facing
starvation. Also, a person whose fat cells have been
emptied will feel hunger and try to “fill them up” again.
34. Exercise is a healthier way to lose weight because it
increases the amount of energy used by the body. It
also increases the amount of muscle tissue, which
burns more calories than other types of body tissues
even when resting.
34. Anorexia and bulemia both are both eating disorders
that result in severe weight loss, which may be fatal.
Anorexia is a refusal to eat, whereas bulemics eat and
then eliminate the food. Anorexics appear unhealthy,
while bulemics may appear healthy.
Chapter 4: Cell structure and
function
1.
2.
3.
4.
5.
6.
7.
8.
B
B
A
A
A
B
D
A
9. A
10. A
11. B
12. D
13. A
14. C
15. A
16. B
17. A
18. C
19. B
20. C
21. B
22. A
23. C
24. ribosomes: where proteins are built
lysosomes: break down food
mitochondria: release energy from food
nucleus: information storage, control center
golgi apparatus: packages many materials
vacuoles: store materials such as food or
waste
chloroplasts: convert sun’s energy into food
25. The cell membrane is selectively permeable
because it allows some substances to pass
through but not others.
This is important because cells need certain
molecules inside but some should be kept outside.
26. Arrow A shows molecules going from an area
of less concentration to an area of greater
concentration, which is active transport because
energy is needed to go against the
concentration gradient. Passive transport is
different in that it doesn’t need energy.
27. Receptor molecules, proteins on the surface
of a cell membrane, allow certain molecules to
attach (chemical messengers) thereby enabling
communication between cells.
28. Stability in an organism is maintained by
integration or making all body parts work
together, and control or acting in an organized
and appropriate manner. In animals, this job is
done by the nervous system and the endocrine
system.
29. Cells communicate with each other by having
certain chemicals move in or out of them.
Receptor proteins in the cell membrane act as
docking sites for these chemicals.
30. Every nerve cell does 3 things; it receives,
conducts, and sends nerve impulses.
31. A nerve impulse is the movement of electrical
voltage (energy) changes along the length of a
neuron. The cell membrane is the most
important part of this because electrical voltage
is created by the rapid movement of positive ions
across a cell membrane. These changes trigger
changes further along the membrane.
32. When a nerve impulse reaches the end of a
neuron, it causes the release of chemicals, which
diffuse across the space to the next cell (the
synapse) to the next nerve cell, which causes the
impulse to be carried along.
33.
34. The energy stored in chemical bonds can
be transferred to other newly formed
chemical bonds or released as heat or
light. Cells use this energy for active
transport, heat, or other cell functions.
35. If a cell’s mitochondria were removed, it
would not be able to release energy from
food molecules
36. The spleen was removed to cure leukemia
36. The pancreatic tissues were used for
research; they produced a certain protein
which was later used to make a new
medicine.
36. The legal system was used to determine
whose rights should have precedence,
those of the cell-donor or the researchers.
Chapter 5: Homeostasis and
Enzymes
1.
2.
3.
4.
5.
6.
7.
8.
C
C
A
B
D
C
C
B
9.
10.
11.
12.
13.
14.
15.
16.
17.
D
C
B
C
B
B
B
B
D
18.
19.
20.
21.
22.
23.
24.
25.
26.
A
D
C
B
D
C
B
B
A
27.
28.
29.
30.
31.
32.
33.
34.
A
C
C
D
C
C
B
A
35. Being multicellular increses and organism’s
ability to maintain homeostasis and survive
because it has many different structures and
systems to protect it from external changes.
36. A body cell will be more likely to survive than an
amoeba because the body cell is multicellular.
37. Intercellular fluid is important for homeostasis
because many substances are dissolved in it,
and it allows substances to be exchanged
between cells and blood in the capillaries.
38. B
39. A feedback mechanism has 3 parts:
•
a sensor – something that can detect a change
•
a control unit – something that can recognize the
correct level of something
•
an effector-something that can make changes
40.
•
•
•
•
•
Blood sugar level is too high
pancreas releases insulin (hormone) into blood stream
insulin reduces levels of glucose
blood sugar levels are too low
pancreas releases glucagon to raise blood sugar levels
41. When we exercise, there is an increase in the CO2 levels
in the blood and intercellular fluid, released by muscle
cells breaking down organic compounds for energy. A
structure in the brain detects these increased levels in the
blood passing through the brain, and in the fluid around
the brain cells. The brain sends signals to the chest to
increase the rate of breathing and the amount of air taken
in with each breath. These changes increase the levels
of gas exchange in the lungs, lowering the levels of CO2
in the blood. These lower levels are then detected in the
brain, reversing the other responses.
42. D
*43. Rising external temperatures will be detected by sensors
in the skin, which will send a message to the brain, which
will increase blood vessel dilation and sweating.
Homeostasis means that the body must maintain
constant internal temperatures, regardless of what is
happening outside the body.
44. Staying in the shade prevents the body from
heating up too much in the sun.
45. Stomata, or openings, surrounded by guard
cells on the surface of a leaf, control the loss of
water. When water is abundant, the guard cells
fill (by osmosis) and open to allow water to
evaporate. When water is scarce, they lose
water, and close, preventing water loss.
46. Contractile vacuoles and guard cells both help
maintain levels of water within organisms.
47. Four organ systems used in homeostasis:
• Excretory system: removes wastes and
regulates the chemistry of the body’s fluids
• Nervous system: uses electrochemical
impulses to regulate body functions
• Endocrine system: produces hormones
(chemical messengers) that help regulate
bodily functions
• Immune system: defends the body from
dangerous substances and harmful
microorganisms.
48. D
49. If the temperature of the solution was
increased, the rate of the reaction would slow
down, because enzymes need a certain
temperature to function.
50. A person with a high body temperature would
possibly die because enzymes change their
shape if the temperature changes, and
therefore their function.
51. We must maintain a neutral pH because any
changes affect an enzyme’s shape and its
function.
52. Life on the ISS is different from Earth in that
there is no downward pull from gravity. There is
no up or down, no floors or ceilings. Crews live
in a relatively small space, and sleep wherever
they feel comfortable .
53. The effects of weightlessness are interesting to
scientists because we are not aware of our
bodies’ responses to gravity until we leave the
Earth.
54. Some of the adaptations of the body to living in
a world with gravity include use of signals from
our eyes, from the fluid-filled tubes in our ears,
from pressure receptors on the bottoms of our
feet, and from the distribution of liquids in blood
vessels.
40. Good news: cures bacterial infections
Bad news: Overuse causes antibiotic
resistant strains of bacteria
41. Because it is causing strains of bacteria
to evolve which are resistant to most
commonly used antibiotics
42. Natural selection explains that the
overuse of antibiotics causes the resistant
bacteria to be selected for and to
reproduce causing more dangerous
infections.