DNA Structure and Replication: Interactive Learning Quizzes for Year 12 Biology

Question 1

Which nitrogenous base is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 2

What is the shape of the DNA molecule?

Accepted Answer

Double helix

Answer

Single helix

Answer

Triple helix

Answer

Quadruple helix

Question 3

What is the process by which a duplicate copy of DNA is made?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Mutation

Question 4

What is the main function of primers in DNA replication?

Accepted Answer

To mark the starting point of replication

Answer

To serve as a template for DNA polymerase

Answer

To join the newly synthesized DNA strands

Answer

To prevent the DNA strands from unwinding

Question 5

Which of the following is a defining characteristic of semi-conservative DNA replication?

Accepted Answer

Each new DNA molecule consists of one original strand and one newly synthesized strand

Answer

Each new DNA molecule consists of two original strands

Answer

Each new DNA molecule consists of two newly synthesized strands

Answer

Each new DNA molecule consists of one original strand and two newly synthesized strands

Question 6

What is the primary purpose of the lagging strand during DNA replication?

Accepted Answer

To ensure complete replication of the DNA molecule

Answer

To provide a template for leading strand synthesis

Answer

To prevent DNA unwinding

Answer

To mark the termination point of replication

Question 7

Why is DNA replication essential for maintaining genetic information during cell division and preserving species characteristics?

Accepted Answer

It ensures each new cell has an identical copy of the genetic material.

Answer

It introduces genetic diversity, promoting species evolution.

Answer

It reduces the genetic material in a cell, promoting cell specialization.

Question 8

Which shape best describes the structure of DNA?

Accepted Answer

Double helix

Answer

Single helix

Answer

Triple helix

Answer

Quadruple helix

Question 9

During DNA replication, which strand(s) serve as the template(s)?

Accepted Answer

Both strands

Answer

Leading strand

Answer

Lagging strand

Answer

Neither strand

Question 10

Which of the following is NOT a characteristic of DNA replication?

Accepted Answer

Error-free

Answer

Semi-conservative

Answer

Bidirectional

Answer

Continuous on both strands

Question 11

What are Okazaki fragments?

Accepted Answer

Segments of DNA synthesized on the lagging strand

Answer

Segments of DNA synthesized on the leading strand

Answer

Enzymes that join DNA fragments

Answer

Molecules that prevent DNA replication

Question 12

Which base pairs with adenine in the DNA double helix structure?

Accepted Answer

Thymine

Answer

Cytosine

Answer

Guanine

Answer

Uracil

Question 13

What is the essential function of DNA polymerase during DNA replication?

Accepted Answer

To synthesize new DNA strands by adding nucleotides

Answer

To unwind the DNA helix

Answer

To proofread the newly synthesized DNA

Answer

To separate the two strands of DNA

Question 14

What type of chemical bond primarily mediates the stability of the DNA double helix structure?

Accepted Answer

Hydrogen bond

Answer

Covalent bond

Answer

Ionic bond

Answer

Van der Waals force

Question 15

Which model of DNA replication accurately describes that each new DNA molecule contains one original and one newly synthesized strand?

Accepted Answer

Semi-conservative model

Answer

Conservative model

Answer

Dispersive model

Answer

Random model

Question 16

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

Accepted Answer

Helicase

Answer

Topoisomerase

Answer

Primase

Answer

Ligase

Question 17

Identify the key difference between DNA and RNA molecules in terms of their constituent building blocks:

Accepted Answer

DNA contains thymine, while RNA contains uracil.

Answer

DNA is single-stranded, while RNA is double-stranded.

Answer

DNA is found exclusively in the nucleus, while RNA is found in both the nucleus and cytoplasm.

Answer

DNA is a polymer of nucleotides, while RNA is a polymer of amino acids.

Question 18

What is the primary function of telomeres in DNA replication?

Accepted Answer

Preventing the loss of genetic information during cell division

Answer

Signaling the cell to stop dividing

Answer

Aiding DNA polymerase in binding to the template strand

Answer

Providing a site for the attachment of regulatory proteins

Question 19

Which technique is commonly used to separate DNA fragments based on their size for analysis?

Accepted Answer

Gel electrophoresis

Answer

Polymerase chain reaction

Answer

DNA sequencing

Answer

Microarray

Question 20

What is the role of helicase in DNA replication?

Accepted Answer

Unwinding the DNA double helix

Answer

Synthesizing new DNA strands

Answer

Joining newly synthesized DNA fragments

Answer

Priming DNA synthesis

Question 21

During DNA replication, what are Okazaki fragments?

Accepted Answer

Short fragments of the newly synthesized lagging strand

Answer

Short fragments of the newly synthesized leading strand

Answer

Original fragments of the DNA template

Answer

RNA fragments that serve as primers

Question 22

Who is credited with discovering the double helix structure of DNA?

Accepted Answer

James Watson and Francis Crick

Answer

Charles Darwin

Answer

Gregor Mendel

Answer

Isaac Newton

Question 23

In DNA replication, which enzyme plays the crucial role of synthesizing new DNA strands by utilizing the existing strand as a template?

Accepted Answer

DNA polymerase

Answer

Helicase

Answer

Ligase

Question 24

Which enzyme is responsible for separating the DNA strands during replication?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

Ligase

Answer

Topoisomerase

Question 25

What is the distinctive shape of a DNA molecule?

Accepted Answer

Double helix

Answer

Single helix

Answer

Triple helix

Answer

Quadruple helix

Question 26

During DNA replication, which enzyme is responsible for separating the DNA double helix?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 27

In DNA replication, what is the primary function of the primer?

Accepted Answer

To initiate the synthesis of new DNA strands by polymerase

Answer

To join Okazaki fragments together

Answer

To prevent the unwinding of the DNA double helix

Answer

To proofread the newly synthesized DNA strand

Question 28

Which of the following accurately describes the sequence of events in DNA replication?

Accepted Answer

Helicase unwinds DNA, polymerase synthesizes new strands, ligase joins Okazaki fragments

Answer

Helicase unwinds DNA, ligase joins Okazaki fragments, polymerase synthesizes new strands

Answer

Polymerase synthesizes new strands, helicase unwinds DNA, ligase joins Okazaki fragments

Answer

Ligase joins Okazaki fragments, helicase unwinds DNA, polymerase synthesizes new strands

Question 29

What is the significance of the semiconservative model of DNA replication?

Accepted Answer

It ensures that each daughter cell inherits a copy of the original DNA molecule.

Answer

It protects DNA from damage during replication.

Answer

It accelerates the process of DNA replication.

Answer

It enables genetic diversity.

Question 30

What is the primary role of telomerase in DNA replication?

Accepted Answer

To prevent DNA loss at chromosome ends during replication

Answer

To correct errors in newly synthesized DNA strands

Answer

To unwind the DNA double helix during replication

Answer

To connect Okazaki fragments

Question 31

Which of the following is not a possible consequence of DNA damage?

Accepted Answer

Improved immune function

Answer

Cancer

Answer

Birth defects

Answer

Aging

Question 32

Identify the sugar molecule that forms the backbone of a DNA molecule.

Accepted Answer

Deoxyribose

Answer

Glucose

Answer

Ribose

Answer

Fructose

Question 33

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

Accepted Answer

Helicase

Answer

DNA Polymerase

Answer

RNA Polymerase

Answer

Ligase

Question 34

Describe the primary function of RNA primers in DNA replication.

Accepted Answer

Providing a starting point for DNA Polymerase

Answer

Proofreading the newly synthesized DNA strand

Answer

Joining the Okazaki fragments

Answer

Unwinding the DNA double helix

Question 35

Which region of DNA contains the genetic instructions for synthesizing a protein?

Accepted Answer

Exon

Answer

Intron

Answer

Promoter

Answer

Terminator

Question 36

What is the process by which DNA is copied into RNA?

Accepted Answer

Transcription

Answer

Translation

Answer

Replication

Answer

Mutation

Question 37

Which characteristic distinguishes eukaryotic DNA from prokaryotic DNA?

Accepted Answer

Containing introns

Answer

Circular structure

Answer

Absence of association with histones

Answer

Presence in the cytoplasm

Question 38

Which component is NOT present in the deoxyribonucleotide found in DNA?

Accepted Answer

Ribose sugar

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Nitrogenous base

Question 39

During DNA replication, what is the primary outcome in terms of the number and nature of the daughter DNA molecules?

Accepted Answer

Two identical copies of DNA

Answer

Two different copies of DNA

Answer

One identical and one different copy of DNA

Answer

Three identical copies of DNA

Question 40

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 41

During DNA replication, which strand is synthesized continuously without the need for RNA primers?

Accepted Answer

Leading strand

Answer

Lagging strand

Answer

Both strands

Answer

Neither strand

Question 42

What is the primary function of telomerase in DNA replication?

Accepted Answer

Preventing the shortening of telomeres

Answer

Extending the 5' ends of daughter strands

Answer

Extending the 3' ends of daughter strands

Answer

Initiating DNA replication

Question 43

A mutation that results in the substitution of one amino acid for another amino acid in a protein is referred to as a:

Accepted Answer

Missense mutation

Answer

Nonsense mutation

Answer

Frameshift mutation

Answer

Silent mutation

Question 44

Which technique is commonly used for analyzing the sequence of DNA fragments?

Accepted Answer

DNA sequencing

Answer

PCR

Answer

Gel electrophoresis

Answer

Microarray analysis

Question 45

The sugar-phosphate backbone of DNA is made up of alternating units of:

Accepted Answer

Deoxyribose and phosphates

Answer

Ribose and adenine

Answer

Deoxyribose and thymine

Answer

Ribose and cytosine

Question 46

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

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

RNA primase

Answer

Topoisomerase

Question 47

Which technique is used to amplify specific regions of DNA?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Gel electrophoresis

Answer

Southern blotting

Answer

DNA sequencing

Question 48

What is the shape of the DNA molecule?

Accepted Answer

Double helix

Answer

Single helix

Answer

Triple helix

Answer

Quadruple helix

Question 49

What is the primary function of DNA polymerase III in DNA replication?

Accepted Answer

Synthesizes new DNA strands

Answer

Unwinds the DNA double helix

Answer

Proofreads newly synthesized DNA

Answer

Joins Okazaki fragments

Question 50

True or False: DNA is a single-stranded molecule.

Accepted Answer

False

Answer

True

Question 51

Which of the following is a semi-conservative model of DNA replication?

Accepted Answer

Meselson-Stahl model

Answer

Watson-Crick model

Answer

Cairns model

Answer

Kornberg model