Nucleic Acid Metabolism Quizzes - Test Your Knowledge

Question 1

Which of the following characteristics of DNA polymerase is true?

Accepted Answer

Requires a primer to start DNA synthesis

Accepted Answer

Is inhibited by dideoxyribonucleotides

Answer

Synthesizes DNA in both 5' to 3' and 3' to 5' directions

Answer

Is a highly error-prone enzyme

Question 2

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Nucleases

Question 3

The leading strand during DNA synthesis is synthesized in the:

Accepted Answer

5' to 3' direction, continuously

Answer

3' to 5' direction, continuously

Answer

5' to 3' direction, discontinuously

Answer

3' to 5' direction, discontinuously

Question 4

Which of the following is NOT a type of RNA polymerase found in eukaryotic cells?

Accepted Answer

Reverse transcriptase

Answer

RNA polymerase I

Answer

RNA polymerase II

Answer

RNA polymerase III

Question 5

The site at which transcription begins is primarily determined by:

Accepted Answer

Promoters

Answer

Enhancers

Answer

Terminators

Answer

Ribosome binding sites

Question 6

Which of the following enzymes catalyzes the formation of the 5' cap on eukaryotic mRNA?

Accepted Answer

Guanylyl transferase

Answer

Methyltransferase

Answer

Polyadenylate polymerase

Answer

Helicase

Question 7

The ribosome is the primary site of:

Accepted Answer

Protein synthesis

Answer

RNA synthesis

Answer

DNA synthesis

Answer

Lipid synthesis

Question 8

The genetic code is:

Accepted Answer

Triplet

Answer

Quadruplet

Answer

Quintuplet

Answer

Hexplet

Question 9

Which of the following is a non-coding RNA molecule that is involved in RNA splicing?

Accepted Answer

Small nuclear RNA

Answer

Transfer RNA

Answer

Ribosomal RNA

Answer

Messenger RNA

Question 10

How does RNA interference contribute to gene silencing, and what are its potential therapeutic applications?

Accepted Answer

RNA interference silences genes by targeting their mRNA for degradation.

Answer

RNA interference inhibits gene silencing by altering DNA methylation patterns.

Answer

RNA interference has no role in therapeutic applications.

Question 11

Telomerase plays a crucial role in maintaining chromosome stability. How does telomerase accomplish this?

Accepted Answer

Extends 3' ends of chromosomes with telomeric repeats

Answer

Shortens telomeres to trigger cell cycle arrest

Answer

Repairs damaged telomeres after DNA replication

Answer

Regulates gene expression in telomeric regions

Question 12

How do epigenetic modifications, such as DNA methylation and histone modification, influence gene expression?

Accepted Answer

Alter the accessibility of DNA to transcription factors

Answer

Change the rate of DNA replication

Answer

Alter the stability of RNA transcripts

Answer

Modify the amino acid sequence of translated proteins

Question 13

During translation, which tRNA anticodon would pair with the codon 5'-GAC-3'?

Accepted Answer

5'-CGU-3'

Answer

5'-GUC-3'

Answer

5'-CUG-3'

Answer

5'-AUG-3'

Question 14

During rRNA synthesis, which molecule provides the template for the new RNA strand?

Accepted Answer

DNA

Answer

mRNA

Answer

tRNA

Answer

rRNA

Question 15

Which of the following is the primary function of DNA repair?

Accepted Answer

Correcting damaged DNA

Answer

Altering the sequence of DNA

Answer

Introducing new mutations into DNA

Answer

Transcribing DNA into RNA

Question 16

DNA modification by the addition of a methyl group to a cytosine base is known as:

Accepted Answer

DNA methylation

Answer

DNA replication

Answer

DNA transcription

Answer

DNA repair

Question 17

Which of the following is used as a primer to initiate DNA synthesis?

Accepted Answer

RNA primer

Answer

DNA primer

Answer

Protein primer

Answer

No primer is required

Question 18

The enzyme responsible for unwinding the DNA helix during replication is:

Accepted Answer

Helicase

Answer

Gyrase

Answer

Polymerase

Answer

Ligase

Question 19

The process by which an RNA molecule is synthesized using a DNA template is known as:

Accepted Answer

Transcription

Answer

Replication

Answer

Translation

Answer

Splicing

Question 20

Which type of RNA is involved in the transfer of amino acids during protein synthesis?

Accepted Answer

tRNA

Answer

mRNA

Answer

rRNA

Answer

snRNA

Question 21

The process of removing non-coding introns from pre-mRNA during RNA processing is called:

Accepted Answer

Splicing

Answer

Polyadenylation

Answer

Capping

Answer

Editing

Question 22

Which factor is essential for the ribosome's movement along the mRNA during translation?

Accepted Answer

Elongation factor G (EF-G)

Answer

Initiation factor 1 (IF1)

Answer

Termination factor 1 (RF1)

Answer

Splicing factor 1 (SF1)

Question 23

Which of the following is NOT a function of transcription factors in the initiation of RNA synthesis?

Accepted Answer

Synthesizing RNA molecules

Answer

Binding to specific DNA sequences upstream of the transcription start site

Answer

Interacting with RNA polymerase to facilitate its binding to the promoter

Answer

Remodeling the chromatin structure to enhance DNA accessibility

Question 24

In the context of cancer development, how does gene amplification contribute to tumorigenesis?

Accepted Answer

Gene amplification increases gene dosage, leading to overexpression of oncoproteins and contributing to tumor development and progression.

Answer

Gene amplification suppresses tumor suppressor gene expression, allowing uncontrolled cell proliferation.

Answer

Gene amplification has no significant impact on cancer development or progression.

Answer

Gene amplification only occurs in the early stages of cancer and is not involved in later stages.

Question 25

How does alternative splicing primarily contribute to the diversity of proteins?

Accepted Answer

By producing multiple protein forms from a single gene

Answer

By combining exons and introns in different ways

Answer

By adding a poly(A) tail to RNA transcripts

Answer

By occurring only in eukaryotic organisms

Question 26

Which enzyme is responsible for RNA synthesis using a DNA template?

Accepted Answer

RNA polymerase

Answer

DNA polymerase

Answer

Reverse transcriptase

Question 27

Which of the following enzymes directly catalyzes the covalent addition of nucleotides to the 3' end of a growing DNA strand, synthesizing a new DNA molecule?

Accepted Answer

DNA polymerase

Answer

RNA polymerase

Answer

Primase

Answer

Ligase

Question 28

In DNA replication, what is the significance of the origin of replication?

Accepted Answer

It is the specific DNA sequence where replication initiates and unwinds

Answer

It is the site where termination of replication occurs

Answer

It contains the genetic code for a specific protein

Question 29

Which of the following is a type of RNA modification that plays a crucial role in altering gene expression and regulating cellular processes?

Accepted Answer

Methylation

Answer

Glycosylation

Answer

Phosphorylation

Answer

Hydroxylation

Question 30

What is the primary purpose of DNA repair mechanisms in maintaining genome integrity?

Accepted Answer

To identify and rectify errors or damage in DNA structure or sequence, ensuring the preservation of genetic information

Answer

To initiate and regulate transcription

Answer

To promote genetic recombination and facilitate gene diversification

Question 31

What is the primary function of telomerase in maintaining the stability of chromosomes during cell division?

Accepted Answer

It adds nucleotides to the ends of chromosomes, compensating for the loss that occurs during replication, preventing chromosome shortening and maintaining genomic integrity

Answer

It promotes the alignment and segregation of chromosomes during cell division

Answer

It repairs damaged DNA sequences within the chromosome

Question 32

Which of the following is a type of genetic mutation that involves the insertion of one or more nucleotides into the DNA sequence?

Accepted Answer

Insertion

Answer

Translocation

Answer

Substitution

Answer

Duplication

Question 33

In molecular biology, what is the process by which an RNA molecule is synthesized using a DNA template as a guide?

Accepted Answer

Transcription

Answer

Replication

Answer

Polymerization

Answer

Translation

Question 34

Which of the following types of RNA molecules plays a role in regulating gene expression by targeting and inhibiting the translation of specific messenger RNA (mRNA)?

Accepted Answer

microRNA (miRNA)

Answer

messenger RNA (mRNA)

Answer

transfer RNA (tRNA)

Answer

ribosomal RNA (rRNA)

Question 35

In molecular biology, what is the central dogma that describes the fundamental flow of genetic information in biological systems?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein

Answer

Protein is translated into RNA, which is then transcribed into DNA

Answer

RNA is transcribed into DNA, which is then translated into protein

Question 36

Explain the role of telomeres in maintaining chromosome stability and their significance in the aging process.

Accepted Answer

Telomeres prevent chromosome fusions and preserve genomic integrity during cell division.

Accepted Answer

Telomeres shorten with each cell division, contributing to cellular aging and senescence.

Answer

Telomeres initiate DNA replication at the origin of replication.

Answer

Telomeres facilitate chromosome segregation during meiosis.

Question 37

Which enzyme initiates DNA synthesis by synthesizing a short RNA primer in eukaryotic cells?

Accepted Answer

Primase

Answer

Polymerase

Answer

Helicase

Answer

Ligase

Question 38

What is the primary function of RNA polymerase in transcription?

Accepted Answer

Synthesizes RNA using a DNA template

Answer

Repairs DNA damage

Answer

Joins Okazaki fragments

Answer

Unwinds the DNA double helix

Question 39

What is the primary function of DNA methylation?

Accepted Answer

Regulates gene expression

Answer

Enhances DNA stability

Answer

Promotes DNA repair

Answer

Protects DNA from mutations

Question 40

Which of the following is a mechanism involved in repairing damaged DNA?

Accepted Answer

Base excision repair

Answer

Transcription

Answer

DNA replication

Answer

RNA polymerase

Question 41

What is the function of telomerase in maintaining chromosome stability?

Accepted Answer

Adds telomeric repeats to chromosome ends

Answer

Synthesizes new DNA strands

Answer

Unwinds the DNA double helix

Answer

Joins Okazaki fragments

Question 42

Which of the following is an example of a non-coding RNA molecule?

Accepted Answer

microRNA

Answer

rRNA

Answer

mRNA

Answer

tRNA

Question 43

What is the significance of the genetic code?

Accepted Answer

Specifies the amino acid sequence of proteins

Answer

Transmits genetic information

Answer

Regulates gene expression

Answer

Determines the structure of DNA

Question 44

Which enzyme plays a key role in DNA replication by synthesizing new DNA strands?

Accepted Answer

DNA polymerase

Answer

Helicase

Answer

RNA polymerase

Question 45

What is the primary function of ribosomes in protein synthesis?

Accepted Answer

Site of protein assembly

Answer

Synthesizes mRNA

Answer

Repairs DNA damage

Answer

Unwinds the DNA double helix

Question 46

Which enzyme catalyzes the polymerization of deoxyribonucleotides during DNA replication?

Accepted Answer

DNA polymerase III

Answer

Helicase

Answer

RNA polymerase

Answer

Ligase

Question 47

What is the main role of telomerase in DNA replication?

Accepted Answer

Extends the overhangs of chromosomes to prevent shortening

Answer

Initiates DNA synthesis at origins of replication

Answer

Proofreads newly synthesized DNA

Question 48

Which type of RNA molecule carries the genetic information from DNA to the ribosomes for protein synthesis?

Accepted Answer

Messenger RNA (mRNA)

Answer

Small nuclear RNA (snRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Transfer RNA (tRNA)

Question 49

What is the process by which DNA damage is repaired through the removal of damaged nucleotides and replacement with correct ones?

Accepted Answer

Nucleotide excision repair

Answer

Non-homologous end joining

Answer

Base excision repair

Answer

Homologous recombination

Question 50

What is the primary role of microRNAs (miRNAs) in gene expression?

Accepted Answer

Regulate gene expression post-transcriptionally by binding to mRNA and inhibiting its translation

Answer

Initiate protein synthesis

Answer

Catalyze biochemical reactions

Question 51

What is the name of the process by which mRNA is modified with a 5' cap and a 3' poly(A) tail?

Accepted Answer

RNA processing

Answer

RNA transcription

Answer

RNA translation

Question 52

What is the function of introns in eukaryotic genes?

Accepted Answer

Non-coding sequences that are spliced out during RNA processing

Answer

Regulatory sequences that control gene expression

Answer

Coding sequences that are translated into protein