1. 1. The most common catabolic reaction in the human body
is:
A. dehydration.
B: hydrolysis.
C. condensation.
D. elimination.
2. A molecule of DNA contains all of the following
EXCEPT:
A. deoxyribose sugars
8. polypeptide bonds
C. phosphodiester bonds
D. nitrogenous bases
3. Which of the following is a carbohydrate polymer that is
stored. in plants and digestible by animals?
A. starch
B. glycogen
C. cellulose
D. glucose
4. Excessive amounts of nitrogen are found in the urine of
an individual who has experienced a period of extended
fasting. This is most likely due to:
A. glycogenolysis in the liver.
B. the breakdown of body proteins.
C. lipolysis in adipose tissue.
D. a lumpr on the posterior" pituitary causing excessive
ADH secretion.
6. Metabolism of carbohydrate and fat spare protein tissue.
All of the following are (me of fats EXCEPT:
A. Fats may be used in cell structure.
.B. Fats may be used as hormones.
C. Fats are a more efficient form of enery storage than
protems.
. D. Fats are a less efficient form of energy storage than
carbohydrates
7. Which of the following is found in the RNA but not the
DNA of a living cell?
A. thymine
B. a double helix
C. an additional hydroxyl group

2. D. hydrogen bonds
9. Enzymes are required by all living things because
enzymes:
A. raise the free energy of chemical reactions.
B. - properly orient reactants and lower activation energy.
C. increase the temperature of reacting molecules.
D. increase the number of reacting molecules.
10. All of the following must change the rate of an enzymecatalyzed
reaction EXCEPT:
A. changing the pH.
B. lowering the temperature.
C. decreasing the concentration of substrate.
D. adding a noncompetitive inhibitor.
11. Since an increase in temperature increases the reaction
rate, why isn’t the elevation of temperature a method
normally used to accelerate enzyme-catalyzed reactions?
A. Raising the temperature causes the reaction to occur
too quickly.
B. Raising the temperature does not sufficiently surmount
the activation energy barrier.
C. Heat changes the configuration of proteins.
D. Heat does not increase the probability of molecular
collision.
12. Which of the following is (are) true concerning feedback
inhibition?
I. It often acts by inhibiting enzyme activity.
II. it works to prevent a build up of excess nutrients.
Ill. lt only acts through enzymes.
A. I only
B. II only
C. I and II only
D. I, II, and III
13. One mechanism of enzyme inhibition is to inhibit an
enzyme without blocking the active site, but by altering
the shape of the enzyme molecule. This mechanism is
called:
A. competitive inhibition.

3. B. noncompetitive inhibition.
C. feedback inhibition.
D. positive inhibition.
14. The continued production of progesterone caused by the
release of RCG from the growing embryo is an example
of:
A. positive feedback
B. negative feedback
C. feedback inhibition
D. feedback enhancement
15. Peptidases that function in the stomach most likely:
A. increase their function in the small intestine due to
increased hydrogen ion concentration.
B. decrease their function in the small intestine due to
increased hydrogen ion concentration.
C. increase their function in the small intestine due to
decreased hydrogen ion concentration.
D. decrease their function in the small intestine due to
decreased hydrogen ion concentration.
16. The rate of a reaction slows when the reaction is exposed
to a competitive inhibitor. Which of the following might
overcome the effects of the inhibitor?
A. decreasing enzyme concentration
B. increasing temperature
C. increasing substrate concentration
D. The effects of competitive inhibition cannot be
overcome.
17. As electrons are passed from one protein complex to
another, the final electron acceptor of the electrontransport
chain is:
A. ATP
B. H2o
C. NADH
D. O2

4. 18. In a human renal cortical cell, the Krebs cycle occurs in
the:
A. cytosol.
B. mitochondrial matrix.
C. inner mitochondrial membrane.
D. intermembrane space.
19. As electrons move within the electron transport chain,
each intermediate carrier molecule is:
A. oxidized by the preceding molecules and reduced
by the following molecule.
B. reduced by the preceding molecule and oxidized by
the following molecule.
Co' reduced by both the preceding and the following
molecules.
D. oxidized by both the preceding and the following
molecules.
20. In aerobic respiration, the energy from the oxidation of
NADH:
A. directly synthesizes ATP.
B. passively diffuses protons from the intermembrane
space into the matrix.
C. establishes a proton gradient between the intermembrane
space and the mitochondrial matrix.
D. pumps protons through ATP synthase.
21. Which of the following processes occurs under both
aerobic and anaerobic conditions?
A. Fermentation
B. Krebs cycle
C. Glycolysis
D. Oxidative phosphorylation
22. Glycolysis takes place in the cytoplasm of an animal cell.
Which of the following is NOT a product or reactant in
glycolysis?
A. glucose
B. pyruvate
C. ATP
D. 02
23. What is the net ATP production from fermentation?

5. A. OATP
B. 2ATP
C. 4ATP
D. 8ATP
24. Heart and liver cells can produce more ATP for each
molecule of glucose than other cells in the body. This is
most likely results of:
A. a more efficient ATP synthase on the outer mitochondrial
membrane.
B. an additional turn of the Kreb's cycle for each glucose
molecule.
C. a more efficient mechanism for moving NADH produced
in glycolysis into the mitochondrial matrix.
D. production of additional NADH by the citric acid
cycle.
Which of the following is always true concerning the base
composition of DNA?
A. In each single strand, the number of adenine
residues equals the number thymine residues.
B. In each single strand. the number of adenine
residues equals the number of guanine residues.
C. In a molecule of double stranded DNA. the ratio of
adenine residues to thymine residues equals the
ratio of cytosine residues to guanine residues.
D. In a molecule of double stranded DNA. the number
of adenine residues plus thymine residues equals the
-number of cytosine residues plus guanine residues.
26. An mRNA molecule being translated at the rough
endoplasmic reticulum is typically shorter than the gene
from which it was transcribed because:
A. the primary transcript was cut as it crossed the nuclear
membrane.
B. normally multiple copies of the mRNA are produced
and spliced.
C. introns in the primary, transcript are excised.
D. several expressed regions of the primary transcript
have equal numbers of base pairs.
28. Which of the following is NOT true concerning DNA
replication?
A. DNA ligase links the Okazaki fragments

6. B. Helicase unwinds the DNA double helix.
C. Only the sense strand is replicated.
D. DNA strands are synthesized in the 5' to 3' direction.
29. The gene for triose phosphate isomerase ·from maize (a
corn plant) spans over 3400 base pairs of DNA and
contains eight introns and nine exons. Which of the
following would most likely represent the number of
nucleotides found in the mature mRNA after posttranscriptional
processing?
A. 1050
B. 3400
C. 6800
D. 13.600
30. Complementary strands of DNA are held together by:
A. phosphodiester bonds
B. covalent bonds
C. hydrophobic interactions
D. hydrogen bonds
31. Eukaryotic mRNA production occurs in the following
sequence:
A. Transcription from DNA in the cytoplasm followed
by post transcriptional processing on the ribosome
B. Transcription from DNA in the nucleus followed by
post transcriptional processing in the nucleus
C. Tnmslation from DNA in the nucleus followed by
post-transcriptional processing in the nucleus
D. Translation from DNA in the cytoplasm followed
by post-transcriptional processing on the ribosome
33. If each of the following mRNA nucleotide sequences
contains three codons, which one contains a start codon?
A. 3'-AGGCCGUAG-5'
B. 3'-GUACCGAAC-5'
C. 5'-AAUGCGGAC-3'
D. 5'-UAGGAUCCC-3'

7. 34. Translation in a eukaryotic cell is associated with each of
the following organelles or locations EXCEPT:
A. the mitochondrial matrix.
B. the cytosol.
C. the nuclens.
D. the rough endoplasmic reticulum.
35. Which of the following is true concerning the genetic
code?
A. There are more amino acids than codoos.
B. Any change in the nucleotide sequence of a codon
must result in a new amino, acid.
C. The genetic code varies from species to species.
D. There are 64 codons.
36. The large subunit of an 80S ribosome is made from:
A. rRNA only.
B. protein only.
C. rRNA and protein only.
D. rRNA and protein bound by a phospholipid bilayer.
37. A fRNA molecule attaches to histidine. The anticodon
on the tRNA is 5'-AUG-3'. Which of the following
nucleotide sequences in an mRNA molecule might
contain the codon for histidine?
A. 3'-GCUAGGCCU-5'
B. 3'-GGTACCTAC-S'
C. 5'-CATTCTTAC-3'
D. 5'-UCAUGGAUC-3'
38. One difference between prokaryotic and eukaryotic
translation is:
A. eukaryotic ribosomes are larger containing more
subunits.
B. prokaryotic translation may occur simultaneously
with transcription while eukaryotic translation cannot.
C. prokaryotes don't contain supra molecular complexes
such as ribosomes.
D. prokaryotic DNA is circular so does not require a
termination sequence.
39. During translation the growing polypeptide can be found
attached to a tRNA at which site on the ribosome?
A. the E site

8. B. the P site
C. theA site
D. the Z site
40. During translation. a signal peptide is synthesized and
attaches to an SRP complex in order to:
A. inactivate the new protein.
B. activate the new protein.
C. prevent the ribosome from attaching to the endoplasmic
reticulum.
D. direct the ribosome to attach to the endoplasmic
reticulum.
41. How many chromosomes does a human primary spermatocyte
contain?
A. 23
B. 46
C. 92
D. 184
42. In which of the following life cycle phases does
translation, transcription, and replication take place?
A. GI
B. S
C. G2
D. M
43. A scientist monitors the nucleotide sequence of the third
chromosome as a cell undergoes normal meiosis. What is
the earliest point in meiosis at which the scientist can
deduce with certainty the nucleotide sequence of the third
chromosome of each gamete?
A. prophase I
B. metaphase I
C. prophase II
D. telophase II
44. Which of the following is a process undergone by germ
cells only?
A. meiosis
B. mitosis
C. interphase

9. D. cytokinesis
46. Which of the following characterizes mitotic prophase?
A. chromosomal alignment along the equator of the
cell
B. separation of sister chrolh_atids
C. centriole migration to the cell poles
D. cytokinesis
47. All of the following might describe events occurring in
prophase I of meiosis EXCEPT:
A. tetrad formation
B. spindle apparatus formation
C. chromosomal migration
D. genetic recombina,tion
48. When a human female is born, the development of her
oocytes is arrested in:
A. prophase of mitosis
B. prophase I of meiosis
C. prophase II of meiosis
D. interphase
KEY:
1. B
2. B
3.A.
4. B
5. C
6. D
7. C
8. A
9. B
10. C
11. C
12. C
13. B
14. A
15. D
16. C
17. D
18. B
19. B

10. 20. C
21. C
22. D
23. B
24. C
25. C
26. C
27. D
28. C
29. A
30. D
31. B
32. D
33. B
34. C
35. D
36. C
37. D.
38. B
39. B
40. D
41. B
42. B
43. A
44. A
45. D
46. C
47. C
48. B