DNA Structure and Replication: Interactive Quizzes for Year 13 Biology

Question 1

Which of the following correctly describes the complementary base pairing in the DNA double helix?

Accepted Answer

Adenine pairs with Thymine; Guanine pairs with Cytosine

Answer

Adenine pairs with Cytosine; Guanine pairs with Thymine

Answer

Adenine pairs with Guanine; Cytosine pairs with Thymine

Answer

Adenine pairs with Uracil; Guanine pairs with Cytosine

Question 2

The structure of the DNA molecule is a:

Accepted Answer

Double helix

Answer

Single strand

Answer

Triple helix

Answer

Quadruple helix

Question 3

DNA polymerase's primary function during DNA replication is to:

Accepted Answer

Add new nucleotides to the growing DNA strand

Answer

Unwind the DNA double helix

Answer

Join the Okazaki fragments

Answer

Prime the DNA template strand

Question 4

The enzyme responsible for preventing telomere shortening is:

Accepted Answer

Telomerase

Answer

Helicase

Answer

Primase

Answer

Ligase

Question 5

Which technique is used to amplify DNA?

Accepted Answer

Polymerase chain reaction

Answer

DNA fingerprinting

Answer

Gel electrophoresis

Answer

DNA sequencing

Question 6

Identify the components that form the sugar-phosphate backbone of a DNA double helix.

Accepted Answer

Deoxyribose and phosphate groups

Answer

Ribose and phosphate groups

Answer

Deoxyribose and nitrogenous bases

Answer

Ribose and nitrogenous bases

Question 7

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 8

Explain the function of telomeres located at chromosome ends.

Accepted Answer

Prevent loss of genetic information during cell division

Answer

Promote DNA unwinding during replication

Answer

Assist in repairing damaged DNA

Answer

Regulate gene expression

Question 9

What is the outcome of DNA replication?

Accepted Answer

Two identical copies of the original DNA molecule

Answer

One identical and one modified copy of the original DNA molecule

Answer

Two modified copies of the original DNA molecule

Answer

One identical and one complementary copy of the original DNA molecule

Question 10

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

Accepted Answer

Ribose sugar

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Adenine

Question 11

What is the correct base pairing rule for DNA ?

Accepted Answer

A-T, C-G

Answer

A-C, T-G

Answer

A-G, C-T

Answer

T-A, C-G

Question 12

Which of the following is not a type of DNA polymerase?

Accepted Answer

RNA polymerase III

Answer

DNA polymerase I

Answer

DNA polymerase II

Answer

DNA polymerase ε

Question 13

What is the purpose of Okazaki fragments in DNA replication?

Accepted Answer

Short fragments on the lagging strand that are later joined by ligase to form a continuous strand

Answer

Long fragments that make up the leading strand

Answer

Fragments of RNA that are used as primers for DNA synthesis

Answer

Fragments of protein that are involved in DNA unwinding

Question 14

What is the specific function of telomerase in DNA replication?

Accepted Answer

Adds nucleotides to the ends of chromosomes to prevent their shortening

Answer

Unwinds the DNA double helix

Answer

Synthesizes the leading strand

Answer

Joins Okazaki fragments

Question 15

Which of the following is a mutation caused by an insertion of one nucleotide into DNA?

Accepted Answer

Frameshift mutation

Answer

Nonsense mutation

Answer

Missense mutation

Answer

Silent mutation

Question 16

What is the core function of DNA in living organisms?

Accepted Answer

To act as the genetic material, carrying hereditary information

Answer

To transport nutrients

Answer

To provide structural support to cells

Answer

To regulate metabolism

Question 17

The sugar-phosphate backbone of DNA is:

Accepted Answer

Covalently bonded to the deoxyribose sugar

Answer

Hydrogen bonded to the nitrogenous bases

Answer

Connected by glycosidic bonds

Answer

Made up of alternating units of adenine and thymine

Question 18

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Exonuclease

Answer

Ligase

Question 19

The process of adding new nucleotides to the growing DNA strand is carried out by:

Accepted Answer

DNA polymerase

Answer

Primase

Answer

Topoisomerase

Answer

RNA polymerase

Question 20

The leading strand during DNA replication is:

Accepted Answer

Synthesized continuously in the 5' to 3' direction

Answer

Synthesized discontinuously in the 5' to 3' direction

Answer

Synthesized continuously in the 3' to 5' direction

Answer

Synthesized discontinuously in the 3' to 5' direction

Question 21

Which of the following is a consequence of DNA replication?

Accepted Answer

Both A and B.

Answer

Genetic variation

Answer

Cell division

Answer

Protein synthesis

Question 22

The discovery of the double helix structure of DNA is credited to:

Accepted Answer

James Watson and Francis Crick

Answer

Rosalind Franklin and Maurice Wilkins

Answer

Erwin Chargaff and Alfred Hershey

Answer

Barbara McClintock and Harriet Creighton

Question 23

What base pairs with thymine (T) in DNA?

Accepted Answer

Adenine (A)

Answer

Guanine (G)

Answer

Cytosine (C)

Question 24

Which enzyme unwinds the DNA double helix during replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Question 25

Which strand during DNA replication is synthesized discontinuously in the 5' to 3' direction?

Accepted Answer

Lagging strand

Answer

Leading strand

Question 26

Which type of DNA mutation involves the loss of a nucleotide?

Accepted Answer

Deletion

Answer

Substitution

Answer

Insertion

Question 27

What is the function of the origin of replication?

Accepted Answer

Marks the starting point of DNA replication

Answer

Provides the energy for DNA synthesis

Question 28

Which technique separates DNA fragments based on size?

Accepted Answer

Gel electrophoresis

Answer

DNA sequencing

Question 29

Which enzyme joins Okazaki fragments on the lagging strand during DNA replication?

Accepted Answer

Ligase

Answer

Helicase

Answer

Polymerase

Answer

Primase

Question 30

Which nitrogenous base is exclusive to RNA and absent in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Cytosine

Question 31

Which component is not found in a DNA nucleotide?

Accepted Answer

Amino acid

Answer

Nitrogenous base

Answer

Phosphate group

Answer

Ribose sugar

Question 32

What is the correct sequence of nitrogenous bases on the complementary DNA strand to 3'-TACGT-5'?

Accepted Answer

5'-ATGC-3'

Answer

5'-TAC-3'

Answer

5'-AUGCA-3'

Answer

5'-GCATA-3'

Question 33

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

Accepted Answer

DNA helicase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Ligase

Question 34

Which statement about DNA replication is accurate?

Accepted Answer

Semi-conservative, producing one original and one new strand in each new DNA molecule.

Answer

Conservative, preserving the original DNA strands in the new molecules.

Answer

Occurs exclusively in the nucleus.

Answer

Is a continuous process without interruptions.

Question 35

What is the primary function of telomerase in DNA replication?

Accepted Answer

Extending the ends of chromosomes to prevent shortening.

Answer

Proofreading and correcting errors in newly synthesized DNA.

Answer

Unwinding the DNA double helix.

Answer

Joining Okazaki fragments on the lagging strand.

Question 36

Which form of DNA mutation results from the addition of an extra nucleotide?

Accepted Answer

Insertion

Answer

Substitution

Answer

Deletion

Answer

Transversion

Question 37

What is the primary consequence of a frameshift mutation?

Accepted Answer

Alters the reading frame of the genetic code, potentially changing the protein sequence.

Answer

Always produces a premature stop codon.

Answer

Causes the loss of a single nucleotide.

Answer

Has no effect on the protein sequence.

Question 38

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

Accepted Answer

Gel electrophoresis

Answer

PCR

Answer

DNA sequencing

Answer

DNA microarrays

Question 39

What is the spatial arrangement of a DNA molecule?

Accepted Answer

Double-stranded helix

Answer

Single-stranded helix

Answer

Coiled circle

Answer

Flat sheet

Question 40

Which type of chemical bond holds the two strands of DNA together?

Accepted Answer

Hydrogen bond

Answer

Covalent bond

Answer

Ionic bond

Answer

Van der Waals force

Question 41

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 42

What is the purpose of RNA primers in DNA replication?

Accepted Answer

To provide a starting point for DNA synthesis

Answer

To connect the Okazaki fragments together

Answer

To proofread the newly synthesized DNA strands

Answer

To separate the strands of the DNA double helix

Question 43

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

Accepted Answer

Each daughter cell receives one original and one newly synthesized DNA strand

Answer

The entire parental DNA molecule is copied into each daughter cell

Answer

The DNA strands are synthesized continuously

Answer

The replication process occurs outside the nucleus

Question 44

What is the function of telomeres in DNA replication?

Accepted Answer

Prevent the loss of genetic information during cell division

Answer

Facilitate the unwinding of the DNA double helix

Answer

Provide a binding site for RNA primers

Answer

Control the replication of DNA strands

Question 45

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

Accepted Answer

Uracil

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Adenine

Question 46

The structure of DNA can best be described as:

Accepted Answer

Double helix

Answer

Single helix

Answer

Triple helix

Answer

Quadruple helix

Question 47

Which of the following enzymes is responsible for unwinding the DNA double helix during replication?

Accepted Answer

DNA helicase

Answer

DNA polymerase

Answer

DNA ligase

Answer

RNA primase

Question 48

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

Accepted Answer

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

Answer

Each new DNA molecule consists of two newly synthesized strands

Answer

Each new DNA molecule consists of two original strands

Answer

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

Question 49

DNA replication occurs in which phase of the cell cycle?

Accepted Answer

Interphase

Answer

Prophase

Answer

Metaphase

Answer

Anaphase

Question 50

Which of the following mutations would result in a premature stop codon?

Accepted Answer

Nonsense mutation

Answer

Missense mutation

Answer

Silent mutation

Answer

Frameshift mutation

Question 51

PCR (Polymerase Chain Reaction) is a technique used for:

Accepted Answer

Amplifying a specific DNA sequence

Answer

Sequencing a DNA molecule

Answer

Translating DNA into protein

Answer

Cloning a gene

Question 52

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

Accepted Answer

Ribose

Answer

Deoxyribose

Answer

Phosphate

Answer

Adenine

Question 53

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

Accepted Answer

Helicase

Answer

Primase

Answer

Polymerase

Answer

Ligase

Question 54

What is the function of the leading strand during DNA replication?

Accepted Answer

Synthesized continuously in the 5' to 3' direction towards the replication fork

Answer

Synthesized discontinuously in the 5' to 3' direction away from the replication fork

Answer

Contains the origin of replication

Answer

Provides a template for the synthesis of the lagging strand

Question 55

What is the purpose of a primer in DNA replication?

Accepted Answer

To initiate DNA synthesis

Answer

To stabilize the template strand

Answer

To proofread errors in the newly synthesized strand

Answer

To unwind the DNA double helix

Question 56

What is the term for the segment of DNA between two adjacent replication origins?

Accepted Answer

Replication bubble

Answer

Okazaki fragment

Answer

Telomere

Answer

Centromere

Question 57

Which of the following techniques is used for DNA analysis and involves the separation of DNA fragments based on size?

Accepted Answer

Gel electrophoresis

Answer

Polymerase chain reaction (PCR)

Answer

Southern blotting

Answer

Mass spectrometry

Question 58

What is the function of telomerase?

Accepted Answer

To extend the ends of chromosomes

Answer

To protect chromosomes from degradation

Answer

To initiate DNA replication

Answer

To repair damaged DNA

Question 59

The stability of the DNA double helix is primarily maintained by:

Accepted Answer

Hydrogen bonds between complementary base pairs

Answer

Covalent bonds between sugar-phosphate backbones

Answer

Ionic bonds between charged phosphate groups

Answer

Hydrophobic interactions between nitrogenous bases

Question 60

Which enzyme is responsible for separating the two strands of the DNA double helix during replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 61

The origin of replication is important because it:

Accepted Answer

Marks the starting point of DNA replication

Answer

Synthesizes new DNA primers

Answer

Proofreads newly synthesized DNA strands

Answer

Terminates DNA replication

Question 62

Which characteristic describes the leading strand during DNA replication?

Accepted Answer

Synthesized continuously towards the replication fork

Answer

Synthesized discontinuously in short fragments

Answer

Requires a RNA primer

Answer

Has a shorter fragment length than the lagging strand

Question 63

What is the function of telomerase in DNA replication?

Accepted Answer

To maintain the length of telomeres at the ends of chromosomes

Answer

To synthesize new DNA primers

Answer

To proofread newly synthesized DNA strands

Answer

To unwind the DNA double helix

Question 64

Which type of mutation causes a shift in the reading frame of the DNA sequence?

Accepted Answer

Insertion of a single nucleotide

Answer

Deletion of a single nucleotide

Answer

Substitution of a single nucleotide

Answer

Deletion of a large segment of DNA