Question 1

Which experiment provided the definitive evidence that DNA, and not protein, is the genetic material in viruses?

Accepted Answer

The Hershey-Chase experiment

Question 2

Which of the following best describes the structure of a nucleotide found in DNA?

Accepted Answer

A phosphate group, a five-carbon sugar, and a nitrogenous base

Question 3

Which of the following statements about DNA replication is correct?

Accepted Answer

DNA synthesis proceeds in the 5' to 3' direction.

Question 4

What is the role of DNA ligase during DNA replication?

Accepted Answer

It catalyzes the formation of phosphodiester bonds between Okazaki fragments.

Question 5

Which of the following base pairs is stabilized by three hydrogen bonds in DNA?

Accepted Answer

Guanine–Cytosine

Question 6

A mutation in which enzyme would most likely result in increased sensitivity to UV light and a higher risk of skin cancer?

Accepted Answer

Nucleotide excision repair enzyme

Question 7

Which of the following best explains why DNA is a stable molecule suitable for information storage?

Accepted Answer

It is stabilized by phosphodiester linkages, hydrogen bonds, and hydrophobic interactions between bases.

Question 8

During DNA replication, which enzyme is responsible for relieving the tension created ahead of the replication fork?

Accepted Answer

Topoisomerase

Question 9

Which of the following is a correct description of semiconservative replication?

Accepted Answer

Each daughter DNA molecule consists of one parental and one new strand.

Question 10

Which of the following is true regarding Okazaki fragments?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand.

Question 11

Which of the following equations correctly represents the formation of a phosphodiester bond during DNA synthesis?

Accepted Answer

$\mathrm{(dNMP)_{n}} + dNTP \rightarrow (dNMP)_{n+1} + PP_i$

Question 12

A patient is diagnosed with xeroderma pigmentosum (XP). Which cellular process is most likely defective in this patient?

Accepted Answer

Nucleotide excision repair

Question 13

Which of the following statements about DNA polymerase is FALSE?

Accepted Answer

It can initiate DNA synthesis without a primer.

Question 14

Which of the following best describes the directionality of DNA synthesis?

Accepted Answer

DNA is synthesized in the 5' to 3' direction.

Question 15

Which of the following is a purine base found in DNA?

Accepted Answer

Adenine

Question 16

Which enzyme is responsible for synthesizing short RNA primers during DNA replication?

Accepted Answer

Primase

Question 17

If a DNA strand has the sequence 5'-ATCGGTA-3', what is the sequence of the complementary strand?

Accepted Answer

3'-TAGCCAT-5'

Question 18

Which of the following is a consequence of mutations in genes required for DNA repair?

Accepted Answer

Increased risk of cancer

Question 19

Which of the following best explains why DNA polymerization is overall exergonic?

Accepted Answer

The hydrolysis of dNTPs releases energy that drives the reaction.

Question 20

Which of the following proteins prevents separated DNA strands from re-annealing during replication?

Accepted Answer

Single-strand DNA-binding proteins (SSBPs)

Nucleic Acids and DNA: Structure, Synthesis, and Repair

Study Guide - Practice Questions