USABO Open Exam | 100% CORRECT ANSWERs | Verified | Latest Version
Question : What enzyme does HIV use to convert RNA to
DNA?
CORRECT ANSWER : Reverse Transcriptase
Question : The promoter region of a prokaryotic gene is
located ______ to the gene and is the binding site for ______.
CORRECT ANSWER : 5'...RNA polymerase
Question : 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
Question : 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
Question : 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%
Question : 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%
Question : 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
Question : The cell bodies of afferent (sensory) nerves
involved in somatic reflexes are located in the
CORRECT ANSWER : Dorsal root ganglion
Question : Rods and cones are associated with _____ and
_____ vision, respectively.
CORRECT ANSWER : Light/dark...color
Question : Populations that are likely to be living at a density
near the limit of their resources, are characterized as
CORRECT ANSWER : K-selected
Question : 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
Question : What glycolytic product is shuttled to the
mitochondria in aerobic respiration?
CORRECT ANSWER : Pyruvate
Question : During human development, which process leads
to the formation of three germ layers?
CORRECT ANSWER : gastrulation
Question : Telomerase is responsible for _____ the size of
telomeres, and its function is often ____ in carcinogenesis.
CORRECT ANSWER : maintaining ... increased
Question : Which of the following is NOT a mode of natural
selection?
CORRECT ANSWER : sexual selection
Question : Protostomes have _____ and _____ types of
cleavage.
CORRECT ANSWER : spiral ... determinate
Question : Which of the following is NOT a characteristic of
all chordates?