Question 1

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

Accepted Answer

The Hershey-Chase experiment using radioactive labeling of phage DNA and protein

Question 2

Which of the following is NOT a necessary characteristic of hereditary material?

Accepted Answer

It must be able to catalyze metabolic reactions

Question 3

In the classic experiment by Avery, MacLeod, and McCarty, which enzyme treatment destroyed the transforming principle?

Accepted Answer

DNase

Question 4

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

Accepted Answer

One strand runs 5' to 3', and the other runs 3' to 5'

Question 5

If a DNA sample contains 20% adenine, what percentage of guanine would you expect according to Chargaff’s rules?

Accepted Answer

30%

Question 6

Which chemical component is found in RNA but not in DNA?

Accepted Answer

Ribose

Question 7

What is the main structural difference between purines and pyrimidines?

Accepted Answer

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

Question 8

Which of the following best explains why GC base pairs are stronger than AT base pairs?

Accepted Answer

GC pairs form three hydrogen bonds, while AT pairs form two

Question 9

A phosphodiester bond in DNA connects:

Accepted Answer

The 5' phosphate of one nucleotide to the 3' hydroxyl of the next

Question 10

Given the DNA sequence 5'–AGTCTTTA–3', what is the complementary strand (with correct orientation)?

Accepted Answer

3'–TCAGAAAT–5'

Question 11

Which of the following is a real-world application of the central dogma of molecular biology?

Accepted Answer

Using mRNA vaccines to induce protein production in human cells

Question 12

Which of the following statements about the Watson-Crick model of DNA is FALSE?

Accepted Answer

The sugar-phosphate backbone is on the inside of the helix

Question 13

Which experimental result provided evidence that DNA, not protein, is the genetic material based on UV absorption and mutagenesis?

Accepted Answer

DNA and RNA absorb UV light at 260 nm, which is also the wavelength most effective at inducing mutations

Question 14

Which of the following is a difference between B-DNA and Z-DNA?

Accepted Answer

Z-DNA has a zigzag backbone and bases tilted relative to the axis, while B-DNA has bases perpendicular to the axis

Question 15

Which of the following best describes the role of tRNA in the cell?

Accepted Answer

It carries amino acids to the ribosome during translation

Question 16

Which of the following is a correct statement about the complementary nature of DNA?

Accepted Answer

If one strand has the sequence 5'–GATTACA–3', the other strand is 3'–CTAATGT–5'

Question 17

Which of the following is a function of the major groove in the DNA double helix?

Accepted Answer

It allows proteins to recognize specific base sequences for gene regulation

Question 18

Which of the following best explains why the amount of DNA correlates with the number of chromosome sets in a species?

Accepted Answer

Each chromosome contains a single, continuous DNA molecule

Question 19

Which of the following is a correct description of the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} \xrightarrow{	ext{transcription}} 	ext{RNA} \xrightarrow{	ext{translation}} 	ext{protein}$$

DNA Structure and Analysis: Foundations of Genetic Material

Study Guide - Practice Questions