USABO Practice
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.
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
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
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
The order of normal blood flow through the human heart is - correct answer-right atrium,
right ventricle, lungs, left atrium, left ventricle, body
Allopatric speciation refers to species formed after which type of separation: - correct
answer-geographic
Which two functional groups are always found in amino acids? - correct answer-Carboxyl
and amine
Movement of ions across the membrane from higher to lower concentrations through a
channel protein is an example of - correct answer-Facilitated diffusion
Which group of plants has vascular tissue but does not produce seeds?
I. Mosses
II. Ferns
III. Gymnosperms - correct answer-II
Which of the following is true for transport in xylem? - correct answer-Movement through
xylem depends mainly on transpiration
Predation is considered a _________ interaction, while Mutualism is considered a
___________ interaction. - correct answer-+/-, +/+
Which of the following organisms is INCORRECTLY paired with its trophic level? - correct
answer-Beetle - secondary consumer
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.
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
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
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
The order of normal blood flow through the human heart is - correct answer-right atrium,
right ventricle, lungs, left atrium, left ventricle, body
Allopatric speciation refers to species formed after which type of separation: - correct
answer-geographic
Which two functional groups are always found in amino acids? - correct answer-Carboxyl
and amine
Movement of ions across the membrane from higher to lower concentrations through a
channel protein is an example of - correct answer-Facilitated diffusion
Which group of plants has vascular tissue but does not produce seeds?
I. Mosses
II. Ferns
III. Gymnosperms - correct answer-II
Which of the following is true for transport in xylem? - correct answer-Movement through
xylem depends mainly on transpiration
Predation is considered a _________ interaction, while Mutualism is considered a
___________ interaction. - correct answer-+/-, +/+
Which of the following organisms is INCORRECTLY paired with its trophic level? - correct
answer-Beetle - secondary consumer
