USABO Open Questions and Verified

USABO Open Questions and Verified Answers, 100% Score Guarantee Pass (Latest 2025) 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:

• acid therapy.
• cloning.
• genetic engineering.
• gene therapy.
• pluripotency. - Correct Answers ✅C. genetic

engineering.Isolated RNA molecules are generally less stable than DNA at

physiological pH because:

• RNA has ribose.
• RNU is always linear.
• RNA has U instead of T.
• RNA is usually single stranded.
• there are many more RNAse enzymes. - Correct Answers

✅A. RNA has ribose.Which of the following molecules is able to cross the lipid bilayer? 1 / 3

USABO Open Questions and Verified Answers, 100% Score Guarantee Pass (Latest 2025)

• antibodies

B. ATP

• insulin
• Na+
• steroid hormones - Correct Answers ✅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?

• 0.010 min
• 0.346 min
• 0.693 min
• 1.000 min
• 1.440 min - Correct Answers ✅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? 2 / 3

USABO Open Questions and Verified Answers, 100% Score Guarantee Pass (Latest 2025)

• chlorophyll
• cell membrane
• differentiated cell types such as spores, vegetative cells,

and heterocysts

• nucleoid region
• nucleolus - Correct Answers ✅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?

• one of the daughter cells, but not the other, would have

radioactive DNA

• neither of the two daughter cells would be radioactive
• all four bases of the DNA would be radioactive
• radioactive thymine would pair with nonradioactive

guanine

• DNA in both daughter cells would be radioactive - Correct

Answers ✅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:

• / 3