Question 1

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

Accepted Answer

The Hershey-Chase experiment using T2 bacteriophage and E. coli

Question 2

What is the main chemical difference between purines and pyrimidines in DNA?

Accepted Answer

Purines have a double-ring structure, while pyrimidines have a single-ring structure

Question 3

According to Chargaff's rules, which of the following equations is always true for double-stranded DNA?

Accepted Answer

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

Question 4

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

Accepted Answer

DNA ligase

Question 5

In the Meselson-Stahl experiment, what result would you expect after two rounds of replication if DNA replication were dispersive?

Accepted Answer

All DNA molecules would have intermediate density

Question 6

Which of the following best describes the antiparallel nature of DNA?

Accepted Answer

The two strands run in opposite directions: one 5' to 3', the other 3' to 5'

Question 7

Which of the following is a function of telomerase in eukaryotic cells?

Accepted Answer

It extends the ends of linear chromosomes to prevent loss of genetic material

Question 8

What is the role of restriction enzymes in genetic engineering?

Accepted Answer

They cut DNA at specific sequences, allowing for the insertion of new genes

Question 9

Which of the following best explains why smaller DNA fragments move farther during gel electrophoresis?

Accepted Answer

Smaller fragments encounter less resistance and move more easily through the gel matrix

Question 10

What is the main advantage of using Taq polymerase in PCR?

Accepted Answer

It is heat-stable and can withstand the high temperatures used in PCR cycles

Question 11

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

Accepted Answer

A sulfur group

Question 12

Why do cancer cells often have active telomerase, while most somatic cells do not?

Accepted Answer

Active telomerase allows cancer cells to divide indefinitely by maintaining chromosome ends

Question 13

Which of the following best describes the function of DNA polymerase during DNA replication?

Accepted Answer

It adds nucleotides to the 3' end of a growing DNA strand

Question 14

What is the purpose of a cloning vector in gene cloning experiments?

Accepted Answer

To carry foreign DNA into a host cell for replication and expression

Question 15

Which of the following statements about the CRISPR-Cas9 system is correct?

Accepted Answer

It can be programmed to cut specific DNA sequences using guide RNA

Question 16

Which of the following best explains why adenine pairs with thymine in DNA?

Accepted Answer

Adenine and thymine form two hydrogen bonds, fitting the geometry of the double helix

Question 17

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

Accepted Answer

It unwinds the DNA double helix at the replication fork

Question 18

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

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

Question 19

Which of the following is a real-world application of PCR (polymerase chain reaction)?

Accepted Answer

Detecting genetic mutations in medical diagnostics

Question 20

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

Chapter 13: The Molecular Basis of Inheritance – Study Guide

Study Guide - Practice Questions