Molecular Genetics Quizzes: Test Your Knowledge

Question 1

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

Accepted Answer

DNA helicase

Answer

DNA polymerase

Answer

DNA ligase

Answer

Primase

Question 2

Which process creates mRNA from a DNA template?

Accepted Answer

Transcription

Answer

Replication

Answer

Translation

Answer

Mutation

Question 3

Which nitrogenous base is unique to RNA and not present in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 4

In transcription, what is the correct order of events?

Accepted Answer

Pre-initiation complex formation, initiation, elongation, termination

Answer

Pre-initiation complex formation, elongation, initiation, termination

Answer

Initiation, pre-initiation complex formation, elongation, termination

Answer

Termination, pre-initiation complex formation, elongation, initiation

Question 5

Which laboratory technique is used in molecular genetics to separate and analyze DNA fragments based on their size and electrical charge?

Accepted Answer

Gel electrophoresis

Answer

Chromatography

Answer

Polymerase Chain Reaction (PCR)

Answer

Restriction enzyme digestion

Question 6

Which component is NOT present in a nucleotide?

Accepted Answer

Fatty acid

Answer

Phosphate group

Answer

Nitrogenous base

Answer

Ribose sugar

Question 7

Which characteristic of the genetic code enables diverse organisms to use different genes to produce the same protein?

Accepted Answer

Degeneracy of the genetic code

Answer

Universality of the genetic code

Answer

Specificity of the genetic code

Answer

Ambiguity of the genetic code

Question 8

In RNA, which molecule takes the place of Thymine in DNA?

Accepted Answer

Uracil

Answer

Cytosine

Answer

Thymine

Answer

Guanine

Question 9

Which nitrogenous base is NOT found in DNA's structure?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 10

Identify a defining characteristic of the genetic code:

Accepted Answer

Triplet code

Accepted Answer

Redundancy

Answer

Read in a 5' to 3' direction

Answer

Exclusive to eukaryotic organisms

Question 11

Which component is not a part of a nucleotide's structure?

Accepted Answer

Amino acid

Answer

Nitrogenous base

Answer

Phosphate group

Answer

Ribose sugar (RNA) or Deoxyribose sugar (DNA)

Question 12

Consider the DNA sequence 5' - ATGC - 3'. Determine the complementary DNA strand formed through the base pairing rules.

Accepted Answer

3' - TACG - 5'

Answer

3' - ATGC - 5'

Answer

5' - ATGC - 3'

Answer

5' - ACGT - 3'

Question 13

Which molecule is NOT found in a DNA nucleotide?

Accepted Answer

Amino acid

Answer

Nitrogenous base

Answer

Deoxyribose sugar

Answer

Phosphate group

Question 14

Which of the following accurately describes a missense mutation?

Accepted Answer

A mutation that alters the codon for one amino acid to the codon for a different amino acid

Answer

A mutation that leaves the amino acid sequence of a protein unchanged

Answer

A mutation that creates a stop codon in the DNA sequence

Answer

A genetic event involving the duplication and insertion of a DNA segment elsewhere in the genome

Question 15

Which nitrogenous base is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 16

In genetic engineering, which technique uses restriction enzymes to cut DNA at specific nucleotide sequences?

Accepted Answer

Restriction Enzyme Digestion

Answer

Polymerase Chain Reaction (PCR)

Answer

DNA Ligation

Answer

Gel Electrophoresis

Question 17

Which nitrogenous base is not exclusively found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 18

Which molecule is NOT directly involved in protein synthesis?

Accepted Answer

Small nuclear RNA (snRNA)

Answer

Messenger RNA (mRNA)

Answer

Transfer RNA (tRNA)

Answer

Ribosomal RNA (rRNA)

Question 19

Which nitrogenous base is unique to RNA and not found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 20

In molecular genetics, which technique is primarily used for DNA sequencing, a crucial process for determining the order of nucleotides in a DNA molecule?

Accepted Answer

Sanger sequencing

Answer

Microarray

Answer

Polymerase chain reaction (PCR)

Answer

Restriction fragment length polymorphism (RFLP)

Question 21

In eukaryotic cells, which of the following processes is not directly involved in gene expression?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Splicing

Question 22

What is the characteristic shape of a DNA molecule?

Accepted Answer

Double, twisted strands forming a helix

Answer

Single, twisted strand

Answer

Triple, intertwined strands

Answer

Circular, open structure

Question 23

Which nitrogenous base is exclusive to RNA and not found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 24

Which component is NOT found in a nucleotide?

Accepted Answer

Amino acid

Answer

Ribose or deoxyribose

Answer

Phosphate group

Question 25

In translation, which molecule carries the specific amino acid matching the codon on the mRNA?

Accepted Answer

Transfer RNA (tRNA)

Answer

Messenger RNA (mRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Small nuclear RNA (snRNA)

Question 26

Which enzyme plays the primary role in adding nucleotides to the growing DNA strand during DNA replication, facilitating its elongation?

Accepted Answer

DNA polymerase

Answer

Primase

Answer

Topoisomerase

Answer

Ligase

Question 27

Which nitrogenous base is absent from the double helix structure of DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Question 28

Which component is not present in the structure of a nucleotide?

Accepted Answer

Amino Acid

Answer

Nitrogenous Base

Answer

Pentose Sugar

Answer

Phosphate Group

Question 29

In genetic engineering, a specific gene is integrated into a plasmid vector to enable its insertion into a host organism. Which technique achieves this?

Accepted Answer

DNA Ligation

Answer

Polymerase Chain Reaction (PCR)

Answer

Restriction Fragment Length Polymorphism (RFLP)

Answer

Gel Electrophoresis

Question 30

In translation, what is the main role of the small ribosomal subunit?

Accepted Answer

Binding to mRNA and locating the start codon

Answer

Connecting amino acids with peptide bonds

Answer

Releasing the newly formed protein

Answer

Creating mRNA from DNA

Question 31

In genetic engineering, which technique involves inserting a gene of interest into a plasmid vector, allowing its transfer into a host organism for expression?

Accepted Answer

Gene cloning

Answer

RFLP analysis

Answer

Gel electrophoresis

Answer

DNA sequencing

Question 32

Which type of mutation modifies gene expression without altering the nucleotide sequence?

Accepted Answer

Epigenetic modification

Answer

Substitution

Answer

Deletion

Answer

Insertion

Question 33

During transcription, which nucleotide in the RNA molecule pairs with thymine (T) in the DNA template?

Accepted Answer

Uracil (U)

Answer

Adenine (A)

Answer

Guanine (G)

Answer

Cytosine (C)

Question 34

Which component is not found in the structure of a nucleotide?

Accepted Answer

Amino acid

Answer

Nitrogenous base

Answer

Pentose sugar

Answer

Phosphate group

Question 35

In gene expression, what is RNA polymerase's primary function?

Accepted Answer

Transcribe DNA into RNA

Answer

Initiate translation

Answer

Translate mRNA into amino acids

Answer

Unwind DNA during replication

Question 36

Genetic engineering involves altering the genetic material of organisms to create new products or enhance existing ones. Which of the following is a potential drawback of genetic engineering?

Accepted Answer

Potential for unintended consequences

Answer

Increased food production

Answer

Improved medical treatments

Answer

Creation of biofuels

Question 37

Which component is NOT part of the genetic code?

Accepted Answer

Operons

Answer

Codons

Answer

Anticodons

Answer

Start and stop signals

Question 38

Which nitrogenous base is **not** found in DNA's genetic code?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 39

What is the function of introns in gene expression?

Accepted Answer

Introns are non-coding sequences that can influence gene expression.

Answer

Introns are removed during transcription and re-inserted during translation.

Answer

Introns code for the primary structure of proteins.

Answer

Introns are always spliced out of the mature mRNA.

Question 40

In forensic science, how are molecular genetics techniques like DNA profiling and genetic fingerprinting used?

Accepted Answer

To identify individuals and determine family relationships, aiding investigations and resolving legal disputes.

Answer

For medical diagnosis and genetic counseling, with limited forensic applications.

Answer

To provide completely accurate DNA results, eliminating false or inconclusive outcomes in investigations.

Answer

Primarily for detecting genetic disorders, with limited use in criminal investigations.

Question 41

In molecular phylogenetics, how do scientists use genetic data to construct an evolutionary tree?

Accepted Answer

Sequence DNA, align sequences, and analyze them to build a tree

Answer

Extract DNA, amplify it using PCR, and separate fragments using gel electrophoresis

Answer

Create karyotypes, perform FISH, and map genes

Answer

Hybridize DNA, perform Southern blotting, and perform Northern blotting

Question 42

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

Accepted Answer

Gel electrophoresis

Answer

Polymerase chain reaction

Answer

DNA sequencing

Answer

Southern blotting

Question 43

Which base listed below is NOT found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 44

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

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Ligase

Question 45

What type of RNA carries genetic information from the nucleus to the ribosome, providing the instructions for protein synthesis?

Accepted Answer

mRNA

Answer

rRNA

Answer

tRNA

Answer

snRNA

Question 46

What is the term for the code that determines the sequence of amino acids in a protein?

Accepted Answer

Genetic code

Answer

Operon model

Answer

Central dogma

Answer

Transcription-translation

Question 47

Which of the following techniques is commonly used to amplify a specific region of DNA?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Gel electrophoresis

Answer

DNA sequencing

Answer

Restriction enzyme digestion

Question 48

What is the primary function of the promoter region of a gene?

Accepted Answer

Binds to RNA polymerase to initiate transcription

Answer

Codes for the start of the protein sequence

Answer

Terminates the transcription process

Answer

Enhances the translation efficiency of mRNA

Question 49

What type of mutation involves the insertion or deletion of a sequence of nucleotides, causing a shift in the reading frame?

Accepted Answer

Frameshift mutation

Answer

Missense mutation

Answer

Nonsense mutation

Answer

Silent mutation

Question 50

What is the main role of genetic counselors in molecular genetics?

Accepted Answer

Providing information and support

Answer

Conducting genetic tests

Answer

Creating new genetic technologies

Question 51

Which of the following is a potential **drawback** of using molecular genetic techniques in medicine?

Accepted Answer

Increased risk of genetic discrimination

Answer

Enhanced diagnosis of genetic disorders

Answer

Development of tailored treatments

Answer

Potential cure for currently incurable diseases

Question 52

How does epigenetics influence gene regulation, and what are its implications for understanding complex traits and diseases?

Accepted Answer

Epigenetic mechanisms affect gene expression patterns, potentially contributing to complex traits and diseases.

Answer

Epigenetics alters the DNA sequence, leading to changes in gene expression.

Answer

All epigenetic modifications are inherited and passed down to future generations.

Answer

Epigenetics has no practical applications in medicine or biotechnology.

Question 53

Which of the following best describes the primary role of a genetic counselor working with individuals and families affected by genetic conditions?

Accepted Answer

Providing emotional support, information, and guidance about genetic conditions and their implications.

Answer

Conducting genetic tests and analyzing the results.

Answer

Prescribing medications and treatments for genetic conditions.

Answer

Conducting research on the causes and treatment of genetic diseases.

Question 54

How does genetic testing contribute to personalized medicine, and what are its potential advantages and drawbacks?

Accepted Answer

Tailoring treatments to an individual's genes, leading to better health outcomes.

Accepted Answer

Identifying individuals who may be prone to certain genetic conditions.

Accepted Answer

Raising ethical concerns about the privacy of genetic data and potential discrimination.

Answer

Completely eradicating all genetic disorders from future generations.

Question 55

Which of the following is NOT a nitrogenous base found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Thymine

Answer

Guanine

Question 56

The process by which genetic information in DNA is copied into RNA is called:

Accepted Answer

Transcription

Answer

Replication

Answer

Translation

Answer

Mutation

Question 57

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 58

During translation, the ribosome moves along the mRNA molecule in a:

Accepted Answer

5' to 3' direction

Answer

3' to 5' direction

Answer

Random direction

Answer

No specific direction

Question 59

Which of the following is a restriction enzyme?

Accepted Answer

EcoRI

Answer

RNA polymerase

Answer

Helicase

Answer

Ligase

Question 60

The primary goal of the Human Genome Project was to:

Accepted Answer

Sequence the entire human genome

Answer

Treat genetic diseases

Answer

Develop new drugs

Answer

Create genetically modified organisms

Question 61

The genetic code is:

Accepted Answer

Universal for all living organisms

Answer

Specific to each species

Answer

Different for prokaryotes and eukaryotes

Answer

Random and unpredictable

Question 62

The process by which a gene is expressed is known as:

Accepted Answer

Gene expression

Answer

Replication and transcription

Answer

Translation and replication

Answer

Mutation and repair

Question 63

Which enzyme is responsible for unwinding the DNA double helix during replication, allowing access for other proteins involved in the process?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Exonuclease

Question 64

What structure plays a crucial role in assembling amino acids into a polypeptide chain during protein synthesis?

Accepted Answer

Ribosome

Answer

Mitochondrion

Answer

Chromosome

Answer

Lysosome