USABO PREP EXAM QUESTIONS AND
ANSWERS
Regarding enzymes, which of the following is true? Enzymes are composed of a
base that includes ribose, phosphate, and nitrogen.
B. Possess activity that is not affected by pH or temperature.
C. When their 3-D structure is disturbed, they lose some or all of their typical
activity.
D. Supply the energy required to initiate a reaction. E. Works are destroyed
after only one use. ANSWER C. When their 3-D structure is disturbed, they
lose some or all of their typical activity.
Your multicellular organism uses fission for asexual reproduction. Both the
original organism and the excised component develop into fully developed,
healthy creatures when a portion of its body of around 10,000 cells is removed.
One of the children is chosen, and the process is repeated for a total of 123
generations. The organisms that are produced are always healthy. What must be
the case with this species' nuclei?
A. Plasmids are present in the cells.
B. There are several types of DNA polymerase in the cells.
C. Circular DNA contains the majority of the cells' genome.
D. Telomerase is active in the cells.
E. Fissonase is active in the cells. ANSWER D. Active polymerase is present in
the cells.
Which of the following best sums up how a protein's lifespan is controlled?
A. The UTR-coded portion of the sequence marks it for destruction.
B. After proteins have stayed in the cell for a while, they are destroyed by
enormous protein complexes known as ubiquitins.
C. Over time, proteins become methylated; proteasomes break down highly
methylated proteins.
D. Ubiquitins are attached to proteins, and proteasomes identify them and
eliminate the proteins.
ANSWERS
Regarding enzymes, which of the following is true? Enzymes are composed of a
base that includes ribose, phosphate, and nitrogen.
B. Possess activity that is not affected by pH or temperature.
C. When their 3-D structure is disturbed, they lose some or all of their typical
activity.
D. Supply the energy required to initiate a reaction. E. Works are destroyed
after only one use. ANSWER C. When their 3-D structure is disturbed, they
lose some or all of their typical activity.
Your multicellular organism uses fission for asexual reproduction. Both the
original organism and the excised component develop into fully developed,
healthy creatures when a portion of its body of around 10,000 cells is removed.
One of the children is chosen, and the process is repeated for a total of 123
generations. The organisms that are produced are always healthy. What must be
the case with this species' nuclei?
A. Plasmids are present in the cells.
B. There are several types of DNA polymerase in the cells.
C. Circular DNA contains the majority of the cells' genome.
D. Telomerase is active in the cells.
E. Fissonase is active in the cells. ANSWER D. Active polymerase is present in
the cells.
Which of the following best sums up how a protein's lifespan is controlled?
A. The UTR-coded portion of the sequence marks it for destruction.
B. After proteins have stayed in the cell for a while, they are destroyed by
enormous protein complexes known as ubiquitins.
C. Over time, proteins become methylated; proteasomes break down highly
methylated proteins.
D. Ubiquitins are attached to proteins, and proteasomes identify them and
eliminate the proteins.
