A1.2 - Nucleic Acids

Question 1

What are the two main types of nucleic acids?

Answer 1

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

These are the fundamental molecules of heredity.

Question 2

What are the three main components of a nucleotide?

Answer 2

• A phosphate group
• A pentose sugar (5-carbon sugar)
• A nitrogenous base

Question 3

What differentiates DNA from RNA?

Answer 3

The specific type of pentose sugar and nitrogenous base

DNA contains deoxyribose and thymine, while RNA contains ribose and uracil.

Question 4

How many strands does DNA have?

Answer 4

Double-stranded

Question 5

How many strands does RNA have?

Answer 5

Single-stranded

Question 6

What are the base compositions of DNA?

Answer 6

• Adenine (A)
• Guanine (G)
• Cytosine (C)
• Thymine (T)

Question 7

What are the base compositions of RNA?

Answer 7

• Adenine (A)
• Guanine (G)
• Cytosine (C)
• Uracil (U)

Question 8

True or False: Thymine is found in RNA.

Answer 8

False

Question 9

What is the structure of DNA referred to as?

Answer 9

Double helix

Question 10

Who elucidated the DNA double helix structure?

Answer 10

James Watson and Francis Crick in 1953

Question 11

What are the key features of the DNA double helix?

Answer 11

• Two antiparallel strands
• Complementary base pairing
• Hydrogen bonding between base pairs

Question 12

What does ‘antiparallel strands’ mean in the context of DNA?

Answer 12

The two strands run in opposite directions.

Question 13

What is complementary base pairing in DNA?

Answer 13

Adenine (A) pairs with Thymine (T) and Guanine (G) pairs with Cytosine (C)

Question 14

How many hydrogen bonds do A-T pairs form?

Answer 14

Two hydrogen bonds

Question 15

How many hydrogen bonds do G-C pairs form?

Answer 15

Three hydrogen bonds

Question 16

What was the significance of the Hershey-Chase experiment?

Answer 16

Provided evidence that DNA, not protein, is the genetic material

Question 17

What were the two radioactive labels used in the Hershey-Chase experiment?

Answer 17

• Radioactive sulfur (in proteins)
• Radioactive phosphorus (in DNA)

Question 18

What conclusion was drawn from the Hershey-Chase experiment?

Answer 18

DNA, not protein, is the genetic material that enters host cells

Question 19

Fill in the blank: The Watson-Crick model of DNA structure exemplifies the power of integrating different scientific _______.

Answer 19

approaches

Question 20

What is the basic structure of nucleic acids?

Answer 20

Nucleotides make up nucleic acids

Question 21

What is the pentose sugar found in DNA?

Answer 21

Deoxyribose

Question 22

What is the pentose sugar found in RNA?

Answer 22

Ribose