$$\text{A} + \text{G} = \text{T} + \text{C}$$

Question 1

Which experiment provided the first strong evidence that DNA, and not protein, is the genetic material in cells?

Accepted Answer

Avery, MacLeod, and McCarty's transformation experiment with Streptococcus pneumoniae

Question 2

Which of the following best describes the structure of DNA as elucidated by Watson and Crick?

Accepted Answer

A double helix with antiparallel strands and complementary base pairing

Question 3

During DNA replication, which enzyme is responsible for unwinding the DNA double helix?

Accepted Answer

Helicase

Question 4

Which of the following statements about DNA replication in prokaryotes and eukaryotes is correct?

Accepted Answer

Prokaryotes have a single origin of replication, while eukaryotes have multiple origins.

Question 5

Which enzyme synthesizes short RNA primers during DNA replication?

Accepted Answer

Primase

Question 6

What is the main function of DNA ligase during DNA replication?

Accepted Answer

Joining Okazaki fragments on the lagging strand

Question 7

Which of the following best explains why eukaryotic chromosomes shorten with each round of replication?

Accepted Answer

DNA polymerase cannot fully replicate the 3' ends of linear DNA molecules.

Question 8

A mutation in which enzyme would most likely result in increased supercoiling ahead of the replication fork?

Accepted Answer

Topoisomerase

Question 9

Which of the following is a direct consequence of semiconservative DNA replication?

Accepted Answer

Each new DNA molecule consists of one parental and one newly synthesized strand.

Question 10

Which of the following best describes the role of nucleosomes in eukaryotic cells?

Accepted Answer

They package DNA into a more compact structure and regulate gene expression.

Question 11

If a eukaryotic cell has a mutation that disables its mismatch repair system, what is the most likely outcome?

Accepted Answer

An increased rate of mutations in the DNA

Question 12

Which of the following base compositions is consistent with Chargaff's rules for double-stranded DNA?

Accepted Answer

$$	ext{A} + 	ext{G} = 	ext{T} + 	ext{C}$$

Question 13

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, requiring discontinuous synthesis on the lagging strand.

Question 14

A scientist is studying a new drug that inhibits DNA polymerase III in bacteria. Which process will be directly affected?

Accepted Answer

Elongation of new DNA strands during replication

Question 15

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

Accepted Answer

Prokaryotes have circular DNA with one origin of replication; eukaryotes have linear DNA with multiple origins.

Question 16

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

Accepted Answer

DNA polymerase I

Question 17

A patient is diagnosed with a genetic disorder that affects the function of telomerase. Which of the following is a likely consequence?

Accepted Answer

Progressive shortening of chromosome ends with each cell division

Question 18

Which of the following best describes the chemical bond that links nucleotides together in a DNA strand?

Accepted Answer

A phosphodiester bond between the 3' hydroxyl and 5' phosphate groups

Question 19

Which of the following scenarios would most likely result in a failure to initiate DNA replication?

Accepted Answer

A nonfunctional primase enzyme

Question 20

Which of the following is a real-world application of DNA replication knowledge in medicine?

Accepted Answer

Development of antiviral drugs that target viral DNA polymerases

DNA: The Molecular Basis of Inheritance – Study Notes 16

Study Guide - Practice Questions