Question 1

Which of the following best describes the flow of genetic information leading to the synthesis of a cellular component?

Accepted Answer

DNA \rightarrow RNA \rightarrow protein

Question 2

The sugar-phosphate backbone of DNA is held together by which type of bond, and the two strands of the double helix are held together by which type of bond?

Accepted Answer

Covalent bonds; hydrogen bonds

Question 3

If cytosine makes up 38\% of the nucleotides in a DNA sample, what percentage of nucleotides will be thymine? (Assume normal base pairing.)

Accepted Answer

12\%

Question 4

A mutation in the promoter region of a gene is most likely to affect which of the following?

Accepted Answer

The binding of RNA polymerase

Question 5

Which of the following statements about catabolite repression is FALSE?

Accepted Answer

When glucose is present, cAMP levels are high

Question 6

Which of the following best explains why transcription and translation occur simultaneously in prokaryotes but not in eukaryotes?

Accepted Answer

Prokaryotes lack nuclear membranes and introns are absent

Question 7

A base substitution mutation in a gene sometimes does not result in a different amino acid. Which factor accounts for this?

Accepted Answer

Some amino acids are produced from more than one codon

Question 8

Which of the following processes produces multiple copies of a region of DNA?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 9

A new antibiotic is discovered that can also be used to treat cancer. What is the most likely cellular target?

Accepted Answer

DNA replication

Question 10

Why are protozoan and fungal diseases generally more difficult to treat than bacterial infections?

Accepted Answer

Protozoan and fungal cells are similar to human cells

Question 11

Which of the following is NOT a feature of a plasmid used for gene cloning?

Accepted Answer

Ability to remove introns

Question 12

A new antibiotic binds within the sequence AAUAUUAA. Which cellular process is most likely to be disrupted?

Accepted Answer

Transcription

Question 13

Which of the following best describes the mechanism by which nucleoside analogs are used in cancer treatment?

Accepted Answer

They mimic nucleotides and inhibit DNA replication in cancer cells

Question 14

Why is cDNA necessary for cloning a eukaryotic gene into a prokaryotic host cell?

Accepted Answer

cDNA is made from mRNA and lacks introns, which prokaryotes cannot remove

Question 15

Which of the following is NOT associated with DNA fingerprinting?

Accepted Answer

Nucleic acid sequencing

Question 16

Which of the following statements about constitutive enzymes is TRUE?

Accepted Answer

They are always produced and cannot be regulated

Question 17

Which of the following best explains why an antimicrobial such as penicillin has a better therapeutic index than many other antimicrobial agents?

Accepted Answer

Penicillin targets bacterial cell walls, which are absent in human cells

Question 18

Which of the following is a mechanism by which chemical mutagens cause frameshift mutations?

Accepted Answer

Insertion or deletion of bases

Question 19

Which of the following is a plausible reason for the increasing danger of running out of useful antibiotics?

Accepted Answer

Overuse and misuse of antibiotics

Question 20

A patient is treated with acyclovir for a viral infection. What is the primary mechanism of action of this drug?

Accepted Answer

Inhibiting viral DNA replication

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