Question 1

Which scientist's X-ray crystallography images were crucial in the discovery of the double helix structure of DNA?

Accepted Answer

Rosalind Franklin

Question 2

In a double-stranded DNA molecule, if adenine (A) makes up 30% of the bases, what percentage of the bases is guanine (G)?

Accepted Answer

20%

Question 3

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

Accepted Answer

Each daughter DNA molecule contains one old strand and one new strand.

Question 4

What is the sequence of the complementary strand for 5'-ATGGTCG-3'?

Accepted Answer

3'-TACCAGC-5'

Question 5

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

Accepted Answer

Topoisomerase

Question 6

DNA polymerase can only add nucleotides to which end of a growing DNA strand?

Accepted Answer

3' end

Question 7

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are joined together by DNA ligase.

Question 8

What is the main function of single-strand binding proteins during DNA replication?

Accepted Answer

They stabilize single-stranded DNA.

Question 9

Which base pairing is stabilized by three hydrogen bonds?

Accepted Answer

G-C

Question 10

If a DNA molecule is composed of 40% guanine, what is the percentage of thymine?

Accepted Answer

10%

Question 11

Which enzyme synthesizes the short RNA primer required for DNA polymerase to begin synthesis?

Accepted Answer

Primase

Question 12

What is the evolutionary significance of mutations in DNA?

Accepted Answer

They are the source of genetic variation for natural selection.

Question 13

Which of the following is NOT a component of a DNA nucleotide?

Accepted Answer

Ribose sugar

Question 14

Why does DNA replication proceed in both directions from each origin in eukaryotic cells?

Accepted Answer

To increase the speed and efficiency of replication.

Question 15

Which of the following best explains why the width of the DNA double helix is uniform?

Accepted Answer

Purine pairs with pyrimidine.

Question 16

What is the role of DNA ligase in DNA replication?

Accepted Answer

It joins Okazaki fragments together.

Question 17

Which process ensures the faithful transmission of genetic information from parent cell to daughter cells?

Accepted Answer

Accurate replication of DNA

Question 18

Which of the following is a consequence of repeated rounds of DNA replication in linear chromosomes?

Accepted Answer

Shortening of telomeres

Question 19

What is the function of telomerase in germ cells?

Accepted Answer

It lengthens telomeres.

Question 20

Which of the following statements about chromatin is correct?

Accepted Answer

Euchromatin is loosely packed and accessible for gene expression.

The Molecular Basis of Inheritance: DNA Structure and Replication

Study Guide - Practice Questions