Structure and Function of DNA: Interactive Learning Quizzes

Question 1

Which of the following accurately describes the structural features of DNA?

Accepted Answer

The sugar-phosphate backbone forms the DNA helix's inner core, with nitrogenous bases extending outward.

Answer

DNA consists of a single nucleotide strand coiled into a helix.

Answer

Thymine pairs only with adenine in the DNA double helix.

Question 2

Which component is unique to RNA nucleotides and not found in DNA nucleotides?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Deoxyribose

Question 3

Which nitrogenous base is NOT present in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 4

According to the base pairing rule in DNA, which bases pair with each other?

Accepted Answer

A-T, C-G

Answer

A-C, T-G

Answer

A-G, C-T

Answer

T-C, G-A

Question 5

Which enzyme is responsible for unwinding the DNA double helix during DNA replication?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Ligase

Question 6

What is the primary function of telomerase?

Accepted Answer

Maintaining telomere length

Answer

Adding nucleotides to the 3' end of leading strands

Answer

Adding nucleotides to the 3' end of lagging strands

Answer

Initiating DNA synthesis

Question 7

What type of chemical bond joins the deoxyribose sugars in the DNA backbone?

Accepted Answer

Phosphodiester bond

Answer

Glycosidic bond

Answer

Hydrogen bond

Answer

Covalent bond

Question 8

What is the primary role of DNA methylation in gene regulation?

Accepted Answer

Repressing gene expression

Answer

Activating gene expression

Answer

Maintaining DNA integrity

Answer

Initiating DNA replication

Question 9

Which structural feature of DNA enables the processes of transcription and translation, leading to the production of functional proteins?

Accepted Answer

Double-stranded, antiparallel nature

Answer

Sugar-phosphate backbone

Answer

Helical shape

Answer

Presence of introns and exons

Question 10

Enzyme in DNA Replication: Which enzyme plays a crucial role in unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Primase

Answer

Ligase

Question 11

Primer Function in DNA Replication: What is the primary function of primers in DNA replication?

Accepted Answer

Provide a starting point for DNA polymerase to synthesize new DNA strands

Answer

Prevent DNA unwinding

Answer

Stabilize the DNA double helix

Answer

Remove RNA nucleotides from newly synthesized DNA strands

Question 12

DNA Repair Mechanism: Which type of DNA repair mechanism specifically targets and corrects mismatched base pairs?

Accepted Answer

Mismatch repair

Answer

Base excision repair

Answer

Nucleotide excision repair

Answer

Recombinational repair

Question 13

Telomeres in DNA Replication: What is the primary role of telomeres in DNA replication?

Accepted Answer

Protect the ends of chromosomes from degradation during replication

Answer

Regulate gene expression

Answer

Provide a site for DNA polymerase to bind

Answer

Prevent the formation of hairpins at the ends of chromosomes

Question 14

Significance of DNA Recombination: What is the primary significance of DNA recombination?

Accepted Answer

Increasing genetic diversity within a population

Answer

Facilitating the repair of damaged DNA strands

Answer

Being essential for cell division

Answer

Being exclusive to somatic cells

Question 15

DNA Analysis Technique: Which technique is commonly employed to separate and analyze DNA fragments?

Accepted Answer

Gel electrophoresis

Answer

Chromatography

Answer

Spectrophotometry

Answer

Mass spectrometry

Question 16

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

Accepted Answer

Amino acid

Answer

Phosphate group

Answer

Nitrogenous base

Answer

Deoxyribose sugar

Question 17

Who proposed the double helix structure of DNA?

Accepted Answer

James Watson and Francis Crick

Answer

Erwin Chargaff

Answer

Maurice Wilkins and Rosalind Franklin

Answer

Linus Pauling

Question 18

Which of the following is the smallest level of DNA organization?

Accepted Answer

Nucleotide

Answer

Nucleosome

Answer

Chromatin

Answer

Chromosome

Question 19

Which enzyme unwinds the DNA double helix during replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 20

Which of the following enzymes proofreads during DNA replication?

Accepted Answer

Exonuclease

Answer

Helicase

Answer

Polymerase

Answer

Ligase

Question 21

Which of the following is NOT a type of DNA repair mechanism?

Accepted Answer

Transcription repair

Answer

Base excision repair

Answer

Nucleotide excision repair

Answer

Mismatch repair

Question 22

Between which components of DNA is the sequence of nitrogenous bases complementary?

Accepted Answer

Nitrogenous bases

Answer

Sugar-phosphate backbones

Answer

Phosphate groups

Answer

Sugar molecules

Question 23

Which enzyme initiates transcription?

Accepted Answer

RNA polymerase

Answer

Helicases

Answer

Primase

Answer

Ligase

Question 24

The genetic code is read in groups of how many nucleotides?

Accepted Answer

Three

Answer

Two

Answer

Four

Answer

Five

Question 25

Which of the following is NOT a potential consequence of DNA damage?

Accepted Answer

Increased lifespan

Answer

Cancer

Answer

Inherited diseases

Answer

Aging