Question 1

Which pairing of nitrogenous bases in DNA is consistent with the width observed in X-ray diffraction data?

Accepted Answer

Purine + pyrimidine

Question 2

What is the primary function of DNA polymerase during DNA replication?

Accepted Answer

Adds nucleotides to the growing DNA strand

Question 3

During DNA replication, the lagging strand is synthesized in short fragments called:

Accepted Answer

Okazaki fragments

Question 4

Which enzyme is responsible for relieving the tension ahead of the replication fork during DNA replication?

Accepted Answer

Topoisomerase

Question 5

What is the diameter of the DNA double helix?

Accepted Answer

$$2\ 	ext{nm}$$

Question 6

In eukaryotic cells, what problem occurs at the ends of linear chromosomes during DNA replication?

Accepted Answer

DNA polymerase cannot replicate the very end, leading to shorter daughter molecules

Question 7

Which enzyme joins the Okazaki fragments on the lagging strand during DNA replication?

Accepted Answer

DNA ligase

Question 8

What is the correct sequence of enzymes involved in repairing damaged DNA?

Accepted Answer

Nuclease → DNA polymerase → DNA ligase

Question 9

Which of the following best describes semi-conservative replication?

Accepted Answer

Each new DNA molecule contains one parental strand and one new strand

Question 10

What is the distance between adjacent base pairs in the DNA double helix?

Accepted Answer

$$0.34\ 	ext{nm}$$

Question 11

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

Accepted Answer

Adenine

Question 12

In prokaryotic cells, DNA replication begins at:

Accepted Answer

A single origin of replication

Question 13

Which protein prevents the separated DNA strands from re-annealing during replication?

Accepted Answer

Single-strand binding proteins

Question 14

What is the function of primase during DNA replication?

Accepted Answer

Synthesizes short RNA primers

Question 15

Which direction does DNA polymerase synthesize new DNA?

Accepted Answer

$$5' \rightarrow 3'$$

Question 16

What is the chemical bond that links the sugar and phosphate groups in the DNA backbone?

Accepted Answer

Phosphodiester bond

Question 17

Which of the following is NOT a function of DNA repair enzymes?

Accepted Answer

Initiating DNA replication at the origin

Question 18

What is the consequence of repeated rounds of DNA replication at the ends of linear chromosomes without telomerase activity?

Accepted Answer

Chromosomes become shorter

Question 19

Which structure packages DNA in eukaryotic cells and is approximately $$10\ 	ext{nm} in $$diameter?

Accepted Answer

Nucleosome

Question 20

If a DNA molecule has 30% adenine, what percentage of guanine would you expect?

Accepted Answer

20%

DNA Structure and Replication: Foundations of Genetic Inheritance

Study Guide - Practice Questions