Download Unit 3 Review Questions

Unit 3 Review
Questions
AP Biology
1. What was the first organic molecule to be
synthesized in the laboratory?
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A. ammonium cyanate
B. hydrogen cyanide
C. urea
D. acetic acid
E. methane
2. Carbon is an unusual atom in that it can form
multiple bonds. Which statement is NOT true?
a) A carbon-to-carbon cis double bond is the type found in nature
and is associated with cardiovascular health.
b) A carbon-to-carbon trans double bond is made artificially in
food processing and is associated with poor cardiovascular
health.
c) Multiple carbon-to-carbon double bonds located near each
other can absorb light, so they are found in molecules in the
eye or in chloroplasts.
d) Multiple carbon-to-carbon bonds are stronger than single
bonds.
e) Saturated fats are those that have a carbon-to-carbon
double bond and are associated with good health.
3. What type of chemical bond joins a functional
group to the carbon skeleton of a large molecule?
A. covalent bond
B. hydrogen bond
C. ionic bond
D. double bond
E. disulfide bond
4. Which of the following is NOT one of the seven
functional groups found in biological molecules?
A.
B.
C.
D.
E.
amino
hydroxyl
carboxyl
cyanate
phosphate
5. Which functional group behaves as a
weak acid in organic molecules?
A. amino
B. carboxyl
C. carbonyl
D. sulfhydryl
E. hydroxyl
6. Which functional group behaves as a
weak base in organic molecules?
A.
B.
C.
D.
E.
amino
carboxyl
carbonyl
sulfhydryl
hydroxyl
7. Which type of molecule always
contains phosphate groups?
A.
B.
C.
D.
E.
carbohydrates
lipids
proteins
nucleic acids
none of the above
8. What type of isomer is propanal
compared to acetone?
A.
B.
C.
D.
cis-trans isomer
structural isomer
enantiomer
none of the above; these are
not isomers
9. Which type of molecule may contain
sulfhydryl groups?
A. carbohydrate
B. lipid
C. protein
D. nucleic acid
E. all of the above
10. Which functional group is best known for its ability to
change the shape of a molecule without affecting its
reactivity?
A.
B.
C.
D.
E.
amino
carboxyl
sulfhydryl
phosphate
methyl
11. The table below gives the molar ratios of
some of the products from Stanley Miller’s
abiotic synthesis of organic molecules
experiment. What is the molar ratio of serine?
A. 1 mole of serine per mole of glycine
B. 3.0 x 102 moles of serine per mole of glycine
C. 3.0 x 102 moles of glycine per mole of serine
D. 1 mole of serine per 3.0 x 102 moles of glycine
12. The table below gives the molar ratios of some of
the products from Stanley Miller’s abiotic synthesis of
organic molecules experiment. Which amino acid is
present in higher amounts than glycine?
A.
B.
C.
D.
serine
methionine
alanine
serine and methionine
13. The synthetic atmosphere in this
experiment contained H2S instead of water vapor. Which of
these amino acids could not have been produced in Miller’s original abiotic
synthesis experiment?
A.
B.
C.
D.
serine
methionine
alanine
glycine
14. What are the four emergent properties of
water that are important for life?
A. cohesion, expansion upon freezing, high
heat of evaporation, capillarity
B. cohesion, moderation of temperature,
expansion upon freezing, solvent properties
C. moderation of temperature, solvent
properties, high surface tension, capillarity
D. heat of vaporization, high specific heat,
high surface tension, capillarity
E. polarity, hydrogen bonding, high specific
heat, high surface tension
15. Water shows high cohesion and
surface tension and can absorb large
amounts of heat because of large
numbers of which of the following
bonds between water molecules?
A. strong ionic bonds
B. nonpolar covalent bonds
C. polar covalent bonds
D. hydrogen bonds
E. weak ionic bonds
16. Water has an unusually high
specific heat. What does this mean?
A. At its boiling point, water changes from
liquid to vapor.
B. More heat is required to raise the
temperature
of water.
C. Ice floats in liquid water.
D. Salt water freezes at a lower
temperature than pure water.
E. Floating ice can insulate bodies of water.
17. Surfactants reduce surface
tension of a liquid. Which of the
following would result if water was
treated
with
surfactants?
A. Surfactant-treated water droplets
would form a thin film instead of
beading on a waxed surface.
B. Surfactant-treated water would form
smaller droplets when dripping from
a sink.
C. Water striders would sink.
D. All of the above would occur.
E. Only A and C would occur.
18. In a glass of old-fashioned
lemonade, which is the solvent?
A. lemon juice
B. sugar
C. water
D. lemonade mixture
E. ice
19. Skin is coated with a hydrophobic glycolipid.
What would happen if this was not present?
A. Water would be lost from skin cells
more quickly.
B. Skin would swell when swimming.
C. Skin would wrinkle more.
D. A and B only
E. A, B, and C
20. Compared to an acidic solution
at pH 5, a basic solution at pH 8 has
A. 1,000 times more hydrogen ions.
B. 1,000 times less hydrogen ions.
C. 100 times less hydrogen ions.
D. the same number of hydrogen ions
but more hydroxide ions.
E. 100 times less hydroxide ions.
21. Which of the following acts as a
pH buffer in blood?
A. carbonic acid
B. bicarbonate ion
C. carbonate ion
D.hydroxide ion
E. A and B
22. Scientists predict that acidification of
the ocean will lower the concentration of
dissolved carbonate ions (CO32), which are
required for coral reef calcification. To test this hypothesis, what would
be the independent variable?
A. ocean pH
B. the rate of calcification
C. the amount of atmospheric CO2
D. time
E.
volume of seawater
23. Based on this graph, what is the
relationship between carbonate ion
concentration and calcification rate?
A. As the acidity of the seawater increased, the
rate of calcification decreased.
B. As the rate of calcification increased, the
concentration of carbonate ions increased.
C. As the concentration of carbonate ions
increased, the rate of calcification
decreased.
D. As the concentration of
carbonate ions increased,
the rate of calcification
increased.
24. If the seawater carbonate ion
concentration is 250 µmol/kg, what is
the approximate rate of calcification
according to this graph?
A. 5 mmol CaCO3 per m2 per day
B. 10 mmol CaCO3 per m2 per day
C. 15 mmol CaCO3 per m2 per day
D. 20 mmol CaCO3 per m2 per day
25. Polymers are made of connected monomer
subunits that are joined by what type of bonds?
A. ionic bonds
B. covalent bonds
C. hydrogen bonds
D. hydrophobic bonds
26. Silicon (atomic number 14, atomic
weight 28) is in the same column as
carbon in the periodic table of the
elements (group IV). Why isn’t life on
Earth based on silicon, instead of carbon?
A. Silicon is far more rare in the Earth’s crust
than carbon.
B. Silicon cannot form polar covalent bonds
with oxygen.
C. Silicon has a different valence than carbon.
D. Silicon compounds often have very
different physico-chemical properties than
the analogous carbon compounds.
27. Which polysaccharide has the greatest number
of branches?
A. cellulose
B. chitin
C. amylose
D. amylopectin
E. glycogen
28. A polysaccharide you are studying
is found to contain unbranched β
glucose molecules and cannot be
digested by humans. Which
polysaccharide are you studying?
A. cellulose
B. DNA
C. chitin
D. starch
E. glycogen
29. Lipids cannot be considered
polymers because
A. they contain polar covalent bonds.
B. their structure includes carbon
rings.
C. they can be artificially created.
D. their monomers are connected via
ionic bonds.
E. they are not composed of monomer
subunits.
30. All lipids
A. are made from glycerol and fatty
acids.
B. contain nitrogen.
C. have low energy content.
D. are acidic when mixed with water.
E. do not dissolve well in water.
31. Sickle-cell disease is caused by a
mutation in the -hemoglobin gene that
changes a charged amino acid, glutamic
acid, to valine, a hydrophobic amino acid.
Where in the protein would you expect to
find glutamic acid?
A. on the exterior surface of the protein
B. in the interior of the protein, away
from water
C. at the active site, binding oxygen
D. at the heme-binding site
32. Which is not a function of
proteins?
A. help make up membranes
B. carry the code for translation from
the nucleus to the ribosome
C. bind to hormones (hormone
receptor)
D. can be hormones
E. speed chemical reactions
33. How does RNA differ from DNA?
A. DNA encodes hereditary
information; RNA does not.
B. DNA forms duplexes; RNA does not.
C. DNA contains thymine; RNA
contains uracil.
D. all of the above
34. DNA and polypeptide sequences from closely related species are more similar to
each other than sequences from more distantly related species. For the remaining
questions, you will look at amino acid sequence data for the β polypeptide chain of
hemoglobin, often called β-globin. You will then interpret the data to hypothesize
whether the monkey or the gibbon is more closely related to humans.
In the alignment shown below, the letters give the sequences of the 146 amino acids
in β-globin from humans, rhesus monkeys, and gibbons. Because a complete
sequence would not fit on one line, the sequences are broken into segments. The
sequences for the three different species are aligned so that you can compare them
easily. For example, you can see that, for all three species, the first amino acid is “V”
(valine) and the 146th amino acid is “H” (histidine).
Scan along the aligned sequences, letter by letter, noting any positions
where the amino acids in the monkey or gibbon sequences do not match
the human sequence.
34. How many amino acids differ between the monkey and the human
sequences?
A. 2
B. 6
C. 8
D. 10
35. How many amino acids differ between the
gibbon and the human sequences?
A. 1
B. 2
C. 6
D. 8
36. What percent of monkey β-globin
amino acids are identical to the human
sequence? (This is called the percent
identity between the monkey and human
β-globin sequences. Note: 146 amino
acids total.)
A. 5.48%
B. 94.5%
C. 95.9%
D. 98.6%
37. Based on the β-globin alignment, identify the
best hypothesis about how humans are related to
monkeys and gibbons.
A. Monkeys are more closely related to humans than
gibbons are because monkeys’ β-globin sequence has
the lower percent identity with humans.
B. Both monkeys and gibbons are equally unrelated to
humans because neither monkeys nor gibbons have
the exact same
β-globin sequence as humans.
C. Both monkeys and gibbons are equally related to
humans because they both have less than a 10%
difference in
β-globin sequence with humans.
D. Gibbons are more closely related to humans than
monkeys are because the gibbon β-globin sequence
is a closer match with the human sequence.
38. What other evidence could you
use to analyze evolutionary
relatedness among gibbons,
monkeys, and humans?
A. the amino acid sequences of other
proteins from gibbons, monkeys, and
humans
B. the amount of habitat overlap among
gibbons, monkeys, and humans
C. the β-globin amino acid sequence from
gorillas
D. the frequency of albinism (mutants that
lack hair and skin pigment) in populations
of gibbons, monkeys, and humans