CLEP - Biology DNA Structure and Replication Questions and Answers

Question 1

During DNA replication, the enzyme responsible for unzipping the double helix by breaking the hydrogen bonds between complementary bases is known as:

Accepted Answer

Helicase

Answer

DNA Polymerase

Answer

Ligase

Answer

Primase

Question 2

A segment of DNA is found to have 30% adenine. According to Chargaff's rules, what percentage of the segment is composed of guanine?

Accepted Answer

20%

Answer

30%

Answer

70%

Answer

40%

Question 3

The Meselson-Stahl experiment provided evidence for which model of DNA replication, demonstrating that each new DNA molecule consists of one parental strand and one newly synthesized strand?

Accepted Answer

Semi-conservative replication

Answer

Conservative replication

Answer

Dispersive replication

Answer

Liberal replication

Question 4

In a laboratory setting, a scientist observes that the joining of Okazaki fragments is impaired during DNA replication. A mutation in the gene coding for which of the following enzymes is the most likely cause of this issue?

Accepted Answer

DNA Ligase

Answer

Helicase

Answer

DNA Polymerase III

Answer

Topoisomerase

Question 5

Which of the following statements accurately describes the synthesis of the lagging strand during DNA replication?

Accepted Answer

It is synthesized discontinuously as a series of Okazaki fragments.

Answer

It is synthesized continuously in the 5' to 3' direction toward the replication fork.

Answer

It uses the leading strand as a template for its synthesis.

Answer

It does not require an RNA primer to initiate synthesis.

Question 6

A nucleotide, the basic building block of DNA, is composed of which three components?

Accepted Answer

A deoxyribose sugar, a phosphate group, and a nitrogenous base

Answer

A ribose sugar, a phosphate group, and an amino acid

Answer

A ribose sugar, a nitrogenous base, and an amino acid

Answer

A deoxyribose sugar, a carboxyl group, and a nitrogenous base