USABO Practice Exam Questions &
Answers (Grade A+)
What enzyme does HIV use to convert RNA to DNA? -
correct answer ✅Reverse Transcriptase
The promoter region of a prokaryotic gene is located ______ to the
gene and is the binding site for ______. -
correct answer ✅5'...RNA polymerase
Which of the following is TRUE of prokaryotes?
I. Simultaneous transcription and translation
II. Presence of intron sequences
III. Circular DNA -
correct answer ✅I and III only
Integral transmembrane proteins are proteins imbedded in the cell
membrane. Which of the following amino acids would you MOST
expect to find in the transmembrane region of such proteins? -
correct answer ✅Tryptophan
When the base composition of DNA from bacterium
Mycobacterium tuberculosis was determined, 18% of the bases
were found to be adenine. What is the G + C content in M.
,USABO Practice Exam Questions &
Answers (Grade A+)
tuberculosis? -
correct answer ✅64%
The frequency of individuals affected with an autosomally recessive
inherited disorder is 1 in 4. Assuming that the population affected
by this disease is in Hardy-Weinberg equilibrium, what is the
proportion of carrier individuals in this population? -
correct answer ✅50%
The velocity of action potential conduction across a nerve axon is
increased by the presence of the myelin sheath. In the peripheral
nervous system, what cell myelinates the axon? -
correct answer ✅schwann cell
The cell bodies of afferent (sensory) nerves involved in somatic
reflexes are located in the -
correct answer ✅Dorsal root ganglion
Rods and cones are associated with _____ and _____ vision,
respectively. -
correct answer ✅Light/dark...color
,USABO Practice Exam Questions &
Answers (Grade A+)
Populations that are likely to be living at a density near the limit of
their resources, are characterized as -
correct answer ✅K-selected
In many types of cancer, the function of the p53 gene is lost. Wild-
type p53 is MOST likely to be a -
correct answer ✅tumor suppressor
What glycolytic product is shuttled to the mitochondria in aerobic
respiration? -
correct answer ✅Pyruvate
During human development, which process leads to the formation
of three germ layers? -
correct answer ✅gastrulation
Telomerase is responsible for _____ the size of telomeres, and its
function is often ____ in carcinogenesis. -
correct answer ✅maintaining ... increased
Which of the following is NOT a mode of natural selection? -
correct answer ✅sexual selection
, USABO Practice Exam Questions &
Answers (Grade A+)
Protostomes have _____ and _____ types of cleavage. -
correct answer ✅spiral ... determinate
Which of the following is NOT a characteristic of all chordates? -
correct answer ✅vertebrae
In cardiac muscle, calcium ions can move freely between adjacent
cells through which of the following? -
correct answer ✅gap junctions
Unlike most polypeptide hormones, steroid hormones are unique in
that they -
correct answer ✅Diffuse across cell membranes
In superoxide dismutase 1, an enzyme implicated in amyotrophic
lateral sclerosis (Lou Gehrig's disease), a copper ion is bound to the
active site and is important for enzyme activity. In this enzyme,
copper most likely functions as a(n) -
correct answer ✅cofactor
Answers (Grade A+)
What enzyme does HIV use to convert RNA to DNA? -
correct answer ✅Reverse Transcriptase
The promoter region of a prokaryotic gene is located ______ to the
gene and is the binding site for ______. -
correct answer ✅5'...RNA polymerase
Which of the following is TRUE of prokaryotes?
I. Simultaneous transcription and translation
II. Presence of intron sequences
III. Circular DNA -
correct answer ✅I and III only
Integral transmembrane proteins are proteins imbedded in the cell
membrane. Which of the following amino acids would you MOST
expect to find in the transmembrane region of such proteins? -
correct answer ✅Tryptophan
When the base composition of DNA from bacterium
Mycobacterium tuberculosis was determined, 18% of the bases
were found to be adenine. What is the G + C content in M.
,USABO Practice Exam Questions &
Answers (Grade A+)
tuberculosis? -
correct answer ✅64%
The frequency of individuals affected with an autosomally recessive
inherited disorder is 1 in 4. Assuming that the population affected
by this disease is in Hardy-Weinberg equilibrium, what is the
proportion of carrier individuals in this population? -
correct answer ✅50%
The velocity of action potential conduction across a nerve axon is
increased by the presence of the myelin sheath. In the peripheral
nervous system, what cell myelinates the axon? -
correct answer ✅schwann cell
The cell bodies of afferent (sensory) nerves involved in somatic
reflexes are located in the -
correct answer ✅Dorsal root ganglion
Rods and cones are associated with _____ and _____ vision,
respectively. -
correct answer ✅Light/dark...color
,USABO Practice Exam Questions &
Answers (Grade A+)
Populations that are likely to be living at a density near the limit of
their resources, are characterized as -
correct answer ✅K-selected
In many types of cancer, the function of the p53 gene is lost. Wild-
type p53 is MOST likely to be a -
correct answer ✅tumor suppressor
What glycolytic product is shuttled to the mitochondria in aerobic
respiration? -
correct answer ✅Pyruvate
During human development, which process leads to the formation
of three germ layers? -
correct answer ✅gastrulation
Telomerase is responsible for _____ the size of telomeres, and its
function is often ____ in carcinogenesis. -
correct answer ✅maintaining ... increased
Which of the following is NOT a mode of natural selection? -
correct answer ✅sexual selection
, USABO Practice Exam Questions &
Answers (Grade A+)
Protostomes have _____ and _____ types of cleavage. -
correct answer ✅spiral ... determinate
Which of the following is NOT a characteristic of all chordates? -
correct answer ✅vertebrae
In cardiac muscle, calcium ions can move freely between adjacent
cells through which of the following? -
correct answer ✅gap junctions
Unlike most polypeptide hormones, steroid hormones are unique in
that they -
correct answer ✅Diffuse across cell membranes
In superoxide dismutase 1, an enzyme implicated in amyotrophic
lateral sclerosis (Lou Gehrig's disease), a copper ion is bound to the
active site and is important for enzyme activity. In this enzyme,
copper most likely functions as a(n) -
correct answer ✅cofactor
