Question 1

Which enzyme is primarily responsible for unwinding the parental double helix at the replication fork during DNA replication?

Accepted Answer

Helicase

Question 2

During DNA replication, which of the following best describes the role of primase?

Accepted Answer

It synthesizes short RNA primers needed to start DNA synthesis.

Question 3

Which of the following statements about the antiparallel nature of DNA is correct?

Accepted Answer

One strand runs 5’ to 3’ and the other runs 3’ to 5’.

Question 4

A mutation disables DNA ligase in a eukaryotic cell. Which of the following would most likely occur during DNA replication?

Accepted Answer

Okazaki fragments would not be joined together on the lagging strand.

Question 5

Which of the following is NOT a requirement for semiconservative DNA replication?

Accepted Answer

Ribosomes

Question 6

In eukaryotic cells, what is the primary function of telomerase?

Accepted Answer

It adds repeating DNA sequences to the ends of chromosomes to prevent shortening.

Question 7

Which of the following best explains why DNA polymerase III cannot initiate DNA synthesis on its own?

Accepted Answer

It requires a free 3’ hydroxyl group to add nucleotides.

Question 8

A scientist observes that a eukaryotic cell has abnormally short chromosomes after several rounds of cell division. Which enzyme is most likely defective?

Accepted Answer

Telomerase

Question 9

Which of the following correctly matches the enzyme with its function during DNA replication?

Accepted Answer

DNA polymerase I: Removes RNA primers and replaces them with DNA

Question 10

Which of the following is a key difference between DNA replication in prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have multiple origins of replication, while prokaryotic cells typically have one.

Question 11

A patient is found to have a mutation that prevents the synthesis of single-strand binding proteins. What is the most likely consequence during DNA replication?

Accepted Answer

The DNA strands would re-anneal before replication could proceed.

Question 12

Which of the following best describes the direction in which the leading strand is synthesized during DNA replication?

Accepted Answer

Continuously in the 5’ to 3’ direction

Question 13

Which of the following equations correctly represents the base pairing in DNA?

Accepted Answer

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

Question 14

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

Accepted Answer

$$20\%$$

Question 15

Which of the following best explains why Okazaki fragments are formed during DNA replication?

Accepted Answer

DNA polymerase III can only synthesize DNA in the 5’ to 3’ direction, so the lagging strand is synthesized discontinuously.

Question 16

Which enzyme prevents the DNA double helix from overwinding ahead of the replication fork?

Accepted Answer

Topoisomerase

Question 17

A researcher adds a chemical that inhibits DNA polymerase I to a cell extract. Which of the following would most likely be observed?

Accepted Answer

RNA primers remain on the newly synthesized DNA.

Question 18

Which of the following is a function of DNA ligase during DNA replication?

Accepted Answer

It joins the 3’ end of DNA that replaces the primer to the rest of the strand.

Question 19

Which of the following best describes semiconservative DNA replication?

Accepted Answer

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

Question 20

Which of the following is a reason why telomeres are important in eukaryotic cells?

Accepted Answer

They protect the ends of chromosomes from degradation and may play a role in aging.

Step-by-Step Guidance for DNA Replication Worksheet

Study Guide - Practice Questions

Study Guide - Flashcards