USABO Open Questions wth Complete Solutions

USABO Open Questions with Complete
Solutions
What enzyme does HIV use to convert RNA to DNA?
[ ] A. DNA gyrase
[ ] B. RNA polymerase
[ ] C. Reverse transcriptase
[ ] D. DNA helicase - Correct Answers ✅C


Which of the following is TRUE of prokaryotes?
I. Simultaneous transcription and translation
II. Presence of intron sequences
III. Circular DNA


[ ] A. I and II only
[ ] B. I and III only
[ ] C. II and III only
[ ] D. I, II, and III - Correct Answers ✅B


The promoter region of a prokaryotic gene is located ______ to
the gene and is the binding site for ______.
[ ] A. 3'...DNA polymerase
[ ] B. 3'...RNA polymerase
[ ] C. 5'...DNA polymerase
[ ] D. 5'...RNA polymerase - Correct Answers ✅D

, USABO Open Questions with Complete
Solutions
. 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?
[ ] A. Lysine
[ ] B. Serine
[ ] C. Tryptophan
[ ] D. Arginine - Correct Answers ✅C Tryptophan
(it is non polar and does not have a charge)


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?
[ ] A. 12.5%
[ ] B. 25%
[ ] C. 50%
[ ] D. 100% - Correct Answers ✅C 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?
[ ] A. Oligodendocyte