Question 1

Which experiment provided the first evidence that DNA can transform bacteria, and what was the key result?

Accepted Answer

Griffith's experiment; showed that heat-killed pathogenic bacteria could transform harmless bacteria

Question 2

In the Hershey-Chase experiment, which isotope was used to label DNA, and what was the conclusion?

Accepted Answer

Phosphorus-32 ($$^{32}P$$); DNA is the genetic material

Question 3

According to Chargaff’s rules, which equation correctly represents the relationship between the bases in DNA?

Accepted Answer

$$A = T$$ and $$G = C$$

Question 4

Which technique was used by Rosalind Franklin to help reveal the structure of DNA?

Accepted Answer

X-ray crystallography

Question 5

What is the significance of the antiparallel structure of DNA for replication?

Accepted Answer

It requires DNA polymerase to synthesize the new strand only in the 5′ to 3′ direction

Question 6

Which enzyme is responsible for relieving the strain caused by the unwinding of the DNA double helix during replication?

Accepted Answer

Topoisomerase

Question 7

During DNA replication, what is the function of primase?

Accepted Answer

Synthesizes a short RNA primer to initiate DNA synthesis

Question 8

Which model of DNA replication was supported by the Meselson-Stahl experiment?

Accepted Answer

Semiconservative model

Question 9

What is the role of DNA ligase during DNA replication?

Accepted Answer

Joins Okazaki fragments on the lagging strand

Question 10

A mutation occurs during DNA replication. Which process is most likely to correct this error before it becomes permanent?

Accepted Answer

Nucleotide excision repair

Question 11

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

Accepted Answer

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

Question 12

Which protein binds to and stabilizes single-stranded DNA during replication?

Accepted Answer

Single-strand binding protein

Question 13

In eukaryotic cells, what is the first level of DNA packing in chromatin?

Accepted Answer

Association with histones to form nucleosomes

Question 14

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are short DNA segments synthesized on the lagging strand

Question 15

A bacterial chromosome is best described as:

Accepted Answer

A double-stranded, circular DNA molecule associated with a small amount of protein

Question 16

Which equation represents the directionality of DNA synthesis by DNA polymerase?

Accepted Answer

$$5' \rightarrow 3'$$

Question 17

What is the evolutionary significance of mutations in DNA?

Accepted Answer

They are the source of genetic variation upon which natural selection operates

Question 18

Which enzyme removes RNA primers and replaces them with DNA nucleotides during replication?

Accepted Answer

DNA polymerase I

Question 19

During DNA replication, which strand is synthesized continuously toward the replication fork?

Accepted Answer

Leading strand

Question 20

Which of the following best explains why DNA polymerase cannot initiate synthesis of a new strand?

Accepted Answer

It requires a free 3′ end provided by an RNA primer

The Molecular Basis of Inheritance: Structure and Replication of DNA

Study Guide - Practice Questions