Question 1

Which experiment provided the first strong evidence that DNA is the genetic material responsible for heredity?

Accepted Answer

Avery, MacLeod, and McCarty's experiment showing transformation with purified DNA

Question 2

According to Chargaff's rules, if a DNA molecule contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

20%

Question 3

Which of the following best describes the structure of a DNA nucleotide?

Accepted Answer

A phosphate group, a deoxyribose sugar, and a nitrogen-containing base

Question 4

Which base pairs with cytosine in DNA, and what type of bond holds them together?

Accepted Answer

Guanine; hydrogen bond

Question 5

What did Hershey and Chase use to demonstrate that DNA, not protein, is the genetic material in bacteriophages?

Accepted Answer

Radioactive phosphorus to label DNA and radioactive sulfur to label protein

Question 6

Which statement about DNA replication is correct?

Accepted Answer

DNA replication is semiconservative, with each new double helix containing one old and one new strand

Question 7

If a DNA strand has the sequence $$5'	ext{-}ATCGGTA-3'$$, what is the complementary sequence?

Accepted Answer

$$3'	ext{-}TAGCCAT-5'$$

Question 8

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

Accepted Answer

Fatty acid

Question 9

What is the significance of hydrogen bonds in the DNA double helix?

Accepted Answer

They connect complementary base pairs, stabilizing the double helix

Question 10

A mutation occurs during DNA replication. Which of the following best describes how mutations can affect an organism?

Accepted Answer

Mutations can be beneficial, neutral, or harmful depending on their effect on the organism

Question 11

Which scientist's work led to the discovery that the amount of adenine equals the amount of thymine in DNA?

Accepted Answer

Erwin Chargaff

Question 12

What is the role of DNA polymerase during DNA replication?

Accepted Answer

It synthesizes new DNA strands by adding nucleotides to the template strand

Question 13

Which of the following best explains why DNA is considered the molecule of heredity?

Accepted Answer

DNA contains instructions for building proteins and is passed from parent to offspring

Question 14

Which process ensures that each daughter cell receives an exact copy of the genetic information during cell division?

Accepted Answer

DNA replication

Question 15

If a mutation changes a base pair from $$A-T to$$ $$G-C$$, what type of mutation has occurred?

Accepted Answer

Substitution

Question 16

Which of the following statements about complementary base pairing in DNA is correct?

Accepted Answer

Adenine pairs with thymine, and cytosine pairs with guanine

Question 17

During DNA replication, what is the function of helicase?

Accepted Answer

It unwinds the DNA double helix

Question 18

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

Accepted Answer

Each new DNA molecule contains one old and one new strand

Question 19

Which of the following is a real-world consequence of mutations in DNA?

Accepted Answer

They can lead to genetic diseases, cancer, or beneficial adaptations

Question 20

Which feature of DNA allows it to encode genetic information?

Accepted Answer

The sequence of nitrogen-containing bases along the DNA strand

DNA: The Molecule of Heredity – Structure, Function, and Replication

Study Guide - Practice Questions