Question 1

Which experiment provided definitive evidence that DNA, not protein, is the genetic material responsible for heredity in cells?

Accepted Answer

Hershey and Chase's experiment using radioactive isotopes in T2 phage

Question 2

According to Chargaff’s law, if a DNA sample contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

20%

Question 3

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

Accepted Answer

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

Question 4

What is the chemical bond that links nucleotides together in a DNA strand?

Accepted Answer

Phosphodiester bond

Question 5

During DNA replication, why must the lagging strand be synthesized in short fragments?

Accepted Answer

Because the lagging strand template runs in the 5' to 3' direction, opposite to the direction DNA polymerase works

Question 6

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 7

What is the function of single-stranded binding proteins (SSBPs) during DNA replication?

Accepted Answer

They keep the two DNA strands separated after helicase unwinds them

Question 8

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

Accepted Answer

Semi-conservative model

Question 9

Why is DNA polymerase unable to replicate the extreme ends of linear chromosomes in eukaryotes?

Accepted Answer

Because there is no 3' end of a preexisting polynucleotide for DNA polymerase to add onto

Question 10

Which enzyme solves the problem of chromosome shortening in eukaryotic cells by replicating telomeres?

Accepted Answer

Telomerase

Question 11

In the context of PCR (Polymerase Chain Reaction), which component is NOT required for DNA replication in a test tube?

Accepted Answer

RNA primer

Question 12

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 13

A mutation occurs during DNA replication because a mismatch is not corrected. Which process failed?

Accepted Answer

Mismatch repair

Question 14

Which of the following is a similarity between PCR and cellular DNA replication?

Accepted Answer

Both require a DNA template, primers, nucleotides, and DNA polymerase

Question 15

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

Accepted Answer

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

Question 16

Which of the following is a real-world consequence of telomerase activity being absent in most adult somatic cells?

Accepted Answer

Telomeres are slowly eroded, leading to cellular aging

Question 17

Which of the following is NOT a function of DNA polymerase during DNA replication?

Accepted Answer

Joining Okazaki fragments together

Question 18

What is the energy source that drives the polymerization of DNA during replication?

Accepted Answer

Release of two phosphates from nucleotide triphosphates

Question 19

Which of the following best describes the semi-conservative model of DNA replication?

Accepted Answer

Each daughter DNA molecule contains one parental strand and one newly synthesized strand

Question 20

Which enzyme is responsible for physically separating the two strands of DNA at the origin of replication?

Accepted Answer

DNA helicase

DNA Structure and Replication: Foundations and Mechanisms

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