Question 1

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

Accepted Answer

The Hershey–Chase experiment

Question 2

What is the primary chemical bond that links deoxyribonucleotides together in a DNA strand?

Accepted Answer

Phosphodiester bond

Question 3

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

Accepted Answer

DNA synthesis proceeds in the 5′ to 3′ direction

Question 4

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

Accepted Answer

Topoisomerase

Question 5

Which of the following statements about Okazaki fragments is TRUE?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand

Question 6

What is the role of telomerase in eukaryotic cells?

Accepted Answer

It adds repetitive DNA sequences to the ends of chromosomes

Question 7

A mutation in which enzyme would most likely result in an inability to remove RNA primers during DNA replication?

Accepted Answer

DNA polymerase I

Question 8

Which of the following best explains why DNA polymerase has a low error rate during DNA replication?

Accepted Answer

It proofreads and removes mismatched nucleotides

Question 9

A patient with xeroderma pigmentosum (XP) is highly sensitive to sunlight. What is the underlying cause of this condition?

Accepted Answer

Defective nucleotide excision repair enzymes

Question 10

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

Accepted Answer

$$\Delta G \u003c 0 ($$exergonic, due to hydrolysis of dNTPs)

Question 11

If a eukaryotic cell lacked telomerase, what would be the most likely consequence after many rounds of cell division?

Accepted Answer

Chromosomes would become progressively shorter

Question 12

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

Each daughter DNA molecule consists of one old and one new strand

Question 13

Which enzyme is responsible for synthesizing the RNA primer required for DNA polymerase to begin DNA synthesis?

Accepted Answer

Primase

Question 14

A scientist exposes bacterial cells to UV light, causing thymine dimers to form. Which DNA repair mechanism is most likely to fix this damage?

Accepted Answer

Nucleotide excision repair

Question 15

Which of the following is a direct result of the antiparallel structure of DNA?

Accepted Answer

One strand is synthesized continuously, the other discontinuously

Question 16

Which of the following best explains why cancer cells often have active telomerase?

Accepted Answer

To allow unlimited cell division by maintaining chromosome length

Question 17

A mutation in a gene encoding a mismatch repair enzyme would most likely result in which of the following?

Accepted Answer

Increased rate of mutations after DNA replication

Question 18

Which of the following is NOT a function of DNA ligase during DNA replication?

Accepted Answer

Removing RNA primers from the lagging strand

Question 19

Which of the following best describes the role of single-strand DNA-binding proteins (SSBPs) during DNA replication?

Accepted Answer

They prevent separated DNA strands from reannealing

Question 20

Which of the following scenarios would most likely result in the formation of a tumor?

Accepted Answer

A mutation in a gene required for DNA repair goes unrepaired

DNA and the Gene: Synthesis and Repair – Study Notes

Study Guide - Practice Questions