Question 1

Which experiment provided the first direct evidence that DNA is the hereditary material responsible for transformation in bacteria?

Accepted Answer

Avery, MacLeod, and McCarty's transformation experiment

Question 2

Which of the following statements about the structure of DNA is CORRECT?

Accepted Answer

The sugar-phosphate backbone is held together by phosphodiester bonds.

Question 3

In the Hershey-Chase experiment, why was $$^{32}P$$ used to label DNA?

Accepted Answer

Because DNA contains phosphorus but not sulfur.

Question 4

Which of the following best describes semiconservative DNA replication?

Accepted Answer

Each daughter duplex contains one parental and one daughter strand.

Question 5

Which enzyme is responsible for synthesizing RNA primers during DNA replication in E. coli?

Accepted Answer

Primase

Question 6

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

Accepted Answer

To join Okazaki fragments by forming phosphodiester bonds

Question 7

Which of the following is a characteristic of Z-form DNA?

Accepted Answer

Left-handed helix

Question 8

A mutation prevents the removal of RNA primers during DNA replication in E. coli. Which enzyme is most likely defective?

Accepted Answer

DNA polymerase I

Question 9

Which of the following best explains why telomeres are necessary in eukaryotic chromosomes?

Accepted Answer

They prevent the loss of essential genetic information during lagging strand synthesis.

Question 10

Which of the following is TRUE regarding DNA proofreading during replication?

Accepted Answer

Proofreading is performed by the 3' to 5' exonuclease activity of DNA polymerase.

Question 11

A researcher observes that a certain DNA molecule has 30% adenine. According to Chargaff's rules, what percentage of guanine should be present?

Accepted Answer

$$20\%$$

Question 12

Which of the following statements about Okazaki fragments is CORRECT?

Accepted Answer

They are joined together by DNA ligase.

Question 13

Which feature of DNA allows it to serve as a template for its own replication?

Accepted Answer

Complementary base pairing

Question 14

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

Accepted Answer

DNA is synthesized in the 5' to 3' direction.

Question 15

A patient’s cancer cells are found to have abnormally high telomerase activity. What is the most likely consequence?

Accepted Answer

Increased chromosome stability and unlimited cell division

Question 16

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

Accepted Answer

Adenine

Question 17

Which process is best described by the following equation: $$	ext{dNTP} ightarrow 	ext{dNMP} + 2	ext{PP}_i$$?

Accepted Answer

Incorporation of a nucleotide into a growing DNA strand

Question 18

Which of the following is a direct result of the antiparallel structure of DNA?

Accepted Answer

The presence of Okazaki fragments on the lagging strand

Question 19

Which of the following best explains why multiple origins of replication are necessary in eukaryotic chromosomes?

Accepted Answer

Eukaryotic chromosomes are much larger and linear, requiring multiple origins for timely replication.

Question 20

Which of the following is a real-world application of DNA replication processes in molecular genetics?

Accepted Answer

Polymerase chain reaction (PCR)

DNA Structure and Replication: Study Notes for Genetics Students

Study Guide - Practice Questions