USABO OPEN EXAM 2
QUESTIONS AND COMPLETE
SOLUTIONS GRADED A+
Your Exam Plug
,Insulin injected by diabetics to control blood sugar levels is derived from bacteria whose DNA has been
modified by the addition of the human gene for insulin, which is then produced by the prokaryotes. This
is an example of:
A. acid therapy.
B. cloning.
C. genetic engineering.
D. gene therapy.
E. pluripotency. - Answer: C. genetic engineering.
Isolated RNA molecules are generally less stable than DNA at physiological pH because:
A. RNA has ribose.
B. RNU is always linear.
C. RNA has U instead of T.
D. RNA is usually single stranded.
E. there are many more RNAse enzymes. - Answer: A. RNA has ribose.
Which of the following molecules is able to cross the lipid bilayer?
A. antibodies
B. ATP
C. insulin
D. Na+
E. steroid hormones - Answer: E. steroid hormones
If the rate constant of a first order reaction that converts substrate S into product P is 0.693 min -1 then
what is the half life of the reaction?
A. 0.010 min
, B. 0.346 min
C. 0.693 min
D. 1.000 min
E. 1.440 min - Answer: D. 1.000 min
The local swimming pool is contaminated with an organism that is causing "swimmers itch." You think
you have identified cyanobacteria in your sample. Which features would you expect this organism to
LACK?
A. chlorophyll
B. cell membrane
C. differentiated cell types such as spores, vegetative cells, and heterocysts
D. nucleoid region
E. nucleolus - Answer: E. nucleolus
Suppose radioactive thymine was added to an actively dividing culture of E.coli bacteria. What would
happen if a cell replicated once in the presence of this radioactive base?
A. one of the daughter cells, but not the other, would have radioactive DNA
B. neither of the two daughter cells would be radioactive
C. all four bases of the DNA would be radioactive
D. radioactive thymine would pair with nonradioactive guanine
E. DNA in both daughter cells would be radioactive - Answer: E. DNA in both daughter cells would be
radioactive
If radioactive sulfur ( 35 S) is used in the culture medium of bacteria that harbor bacteriophage viruses,
it will later appear in:
A. bacterial RNA.
B. bacterial cell walls.
QUESTIONS AND COMPLETE
SOLUTIONS GRADED A+
Your Exam Plug
,Insulin injected by diabetics to control blood sugar levels is derived from bacteria whose DNA has been
modified by the addition of the human gene for insulin, which is then produced by the prokaryotes. This
is an example of:
A. acid therapy.
B. cloning.
C. genetic engineering.
D. gene therapy.
E. pluripotency. - Answer: C. genetic engineering.
Isolated RNA molecules are generally less stable than DNA at physiological pH because:
A. RNA has ribose.
B. RNU is always linear.
C. RNA has U instead of T.
D. RNA is usually single stranded.
E. there are many more RNAse enzymes. - Answer: A. RNA has ribose.
Which of the following molecules is able to cross the lipid bilayer?
A. antibodies
B. ATP
C. insulin
D. Na+
E. steroid hormones - Answer: E. steroid hormones
If the rate constant of a first order reaction that converts substrate S into product P is 0.693 min -1 then
what is the half life of the reaction?
A. 0.010 min
, B. 0.346 min
C. 0.693 min
D. 1.000 min
E. 1.440 min - Answer: D. 1.000 min
The local swimming pool is contaminated with an organism that is causing "swimmers itch." You think
you have identified cyanobacteria in your sample. Which features would you expect this organism to
LACK?
A. chlorophyll
B. cell membrane
C. differentiated cell types such as spores, vegetative cells, and heterocysts
D. nucleoid region
E. nucleolus - Answer: E. nucleolus
Suppose radioactive thymine was added to an actively dividing culture of E.coli bacteria. What would
happen if a cell replicated once in the presence of this radioactive base?
A. one of the daughter cells, but not the other, would have radioactive DNA
B. neither of the two daughter cells would be radioactive
C. all four bases of the DNA would be radioactive
D. radioactive thymine would pair with nonradioactive guanine
E. DNA in both daughter cells would be radioactive - Answer: E. DNA in both daughter cells would be
radioactive
If radioactive sulfur ( 35 S) is used in the culture medium of bacteria that harbor bacteriophage viruses,
it will later appear in:
A. bacterial RNA.
B. bacterial cell walls.
