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USABO OPEN EXAM 2025 ALL
POSSIBLE QUESTIONS LATEST
UPDATE EXAM 285 QUESTIONS
WITH 100% VERIFIED CORRECT
ANSWERS GUARANTEED A +
Question 1: What enzyme does HIV use to convert RNA
to DNA?
CORRECT ANSWER: Reverse Transcriptase
Question 2: The promoter region of a prokaryotic gene is
located ______ to the gene and is the binding site for
______.
CORRECT ANSWER: 5'...RNA polymerase
Question 3: Which of the following is TRUE of
prokaryotes?
- Simultaneous transcription and translation
II. Presence of intron sequences
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III. Circular DNA
CORRECT ANSWER: I and III only
Question 4: 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 5: 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 6: The frequency of individuals affected with an
autosomally recessive inherited disorder is 1 in 4.
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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 7: 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 8: The cell bodies of afferent (sensory) nerves
involved in somatic reflexes are located in the
CORRECT ANSWER: Dorsal root ganglion
Question 9: Rods and cones are associated with _____
and _____ vision, respectively.
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CORRECT ANSWER: Light/dark...color
Question 10: Populations that are likely to be living at a
density near the limit of their resources, are characterized as
CORRECT ANSWER: K-selected
Question 11: 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 12: What glycolytic product is shuttled to the
mitochondria in aerobic respiration?