Question 1

Which carbon of the deoxyribose sugar in DNA is directly bonded to the nitrogenous base?

Accepted Answer

C 1'

Question 2

In a DNA nucleotide, the phosphate group is attached to which carbon of the pentose sugar?

Accepted Answer

C 5'

Question 3

DNA is a polymer of repeating monomers. What is the monomeric unit of DNA?

Accepted Answer

Nucleotide

Question 4

Which of the following best describes the charge of the phosphate group at physiological pH?

Accepted Answer

Negative

Question 5

Given the DNA sequence 5'-GACCGA-3', which end is the 3' end?

Accepted Answer

The end with the A

Question 6

According to Chargaff's rules, if a DNA sample from wheat contains 28.1% adenine, what percentage of thymine would you expect?

Accepted Answer

28.1%

Question 7

During DNA replication, which strand is synthesized discontinuously?

Accepted Answer

Lagging strand

Question 8

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

Accepted Answer

Helicase

Question 9

In gel electrophoresis, DNA fragments migrate toward which electrode?

Accepted Answer

Positive electrode

Question 10

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

Accepted Answer

Eukaryotes have multiple origins of replication per chromosome

Question 11

If a DNA molecule contains 32.8% adenine and 17.7% guanine, what is the expected percentage of cytosine?

Accepted Answer

17.3%

Question 12

Which enzyme joins Okazaki fragments during DNA replication?

Accepted Answer

Ligase

Question 13

What is the function of primase during DNA replication?

Accepted Answer

Synthesizes RNA primers

Question 14

Which of the following best explains why DNA polymerase can only add nucleotides to the 3' end of a growing DNA strand?

Accepted Answer

The 3' end has a free hydroxyl group ($$-OH)$$

Question 15

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

Accepted Answer

Amino acid

Question 16

If a DNA fragment is 500 base pairs long, how many nucleotides does it contain?

Accepted Answer

1000

Question 17

Which of the following statements about Okazaki fragments is TRUE?

Accepted Answer

They are short DNA segments synthesized on the lagging strand

Question 18

Which of the following best describes the direction of DNA synthesis?

Accepted Answer

5' to 3'

Question 19

What would happen if DNA polymerase lacked proofreading ability?

Accepted Answer

Mutation rate would increase

Question 20

Which of the following is a real-world application of gel electrophoresis?

Accepted Answer

Separating DNA fragments by size for genetic fingerprinting

DNA Structure and Replication: Key Concepts and Comparisons

Study Guide - Practice Questions