Molecular Basis of Inheritance: Interactive Learning Quizzes for Medical Students

Question 1

Which of the following nitrogenous bases is NOT present in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Guanine

Question 2

Determine the complementary DNA strand for the following sequence: 5' ATGCGTAC 3'?

Accepted Answer

5' TACGCATG 3'

Answer

5' UACGCATG 3'

Answer

5' GCUGCAG 3'

Answer

5' CGUACGA 3'

Question 3

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

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Primase

Question 4

Which genetic code represents the amino acid methionine?

Accepted Answer

AUG

Answer

UAG

Answer

UAU

Answer

CGT

Question 5

Define a frameshift mutation.

Accepted Answer

A mutation that shifts an entire codon

Answer

A mutation that modifies a single base pair

Answer

A mutation that inserts or deletes a single nucleotide

Answer

A mutation that replaces one base pair with another

Question 6

Describe the function of introns in eukaryotic genes.

Accepted Answer

Being removed during RNA processing

Answer

Encoding proteins

Answer

Regulating gene expression

Answer

Enhancing mRNA stability

Question 7

Which of the following RNA molecules is non-coding?

Accepted Answer

Small nuclear RNA (snRNA)

Answer

Messenger RNA (mRNA)

Answer

Transfer RNA (tRNA)

Answer

Ribosomal RNA (rRNA)

Question 8

State the central dogma of molecular biology.

Accepted Answer

DNA → RNA → Protein

Answer

RNA → DNA → Protein

Answer

Protein → RNA → DNA

Answer

DNA → Protein → RNA

Question 9

During transcription, what is the primary function of RNA polymerase?

Accepted Answer

Synthesizing a complementary RNA strand using DNA as a template

Answer

Unwinding and separating the DNA double helix

Answer

Stabilizing the newly synthesized RNA molecule

Answer

Initiating the translation process

Question 10

The correct sequence of events during protein synthesis is:

Accepted Answer

Replication, transcription, translation

Answer

Transcription, translation, replication

Answer

Translation, transcription, replication

Answer

Replication, translation, transcription

Question 11

Which RNA molecule mentioned below is non-coding?

Accepted Answer

MicroRNA (miRNA)

Answer

Messenger RNA (mRNA)

Answer

Transfer RNA (tRNA)

Answer

Ribosomal RNA (rRNA)

Question 12

The genetic code refers to:

Accepted Answer

A set of rules that determines which amino acid is encoded by each codon

Answer

A sequence of DNA nucleotides that constitutes a gene

Answer

A type of mutation that changes the sequence of amino acids in a protein

Answer

A molecule that carries genetic information from the nucleus to the cytoplasm

Question 13

Which technique is utilized to amplify specific DNA regions?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Gel electrophoresis

Answer

DNA sequencing

Answer

Southern blotting

Question 14

Differentiate between a germline mutation and a somatic mutation:

Accepted Answer

Germline mutations occur in reproductive cells and can be inherited, while somatic mutations occur in non-reproductive cells and are not inherited

Answer

Germline mutations are more prevalent than somatic mutations

Answer

Somatic mutations can lead to cancer, while germline mutations do not

Answer

Germline mutations are inherently harmful, while somatic mutations can be either beneficial or detrimental

Question 15

Which genetic disorder is caused by a defect in DNA repair?

Accepted Answer

Xeroderma pigmentosum

Answer

Sickle cell anemia

Answer

Cystic fibrosis

Answer

Huntington's disease

Question 16

Genetic counseling primarily focuses on:

Accepted Answer

Providing information about the inheritance of genetic disorders and assisting families in informed decision-making regarding screening and treatment

Answer

Diagnosing and treating genetic disorders

Answer

Developing innovative genetic therapies

Answer

Conducting genetic testing

Question 17

The central dogma of molecular biology describes the flow of information from DNA to proteins. Which of the following correctly represents the sequence of events in this dogma?

Accepted Answer

Replication -> Transcription -> Translation

Answer

Transcription -> Replication -> Translation

Answer

Translation -> Replication -> Transcription

Answer

Translation -> Transcription -> Replication

Question 18

The genetic code, which provides instructions for protein synthesis, is composed of which type of molecules?

Accepted Answer

Nucleotides

Answer

Amino acids

Answer

Carbohydrates

Answer

Lipids

Question 19

During DNA replication, which enzyme is responsible for unwinding the DNA double helix, allowing access to the template strands?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Ligase

Question 20

Transfer RNA (tRNA) plays a crucial role in protein synthesis. What is its primary function?

Accepted Answer

Transporting amino acids to the ribosome

Answer

Synthesizing new proteins

Answer

Transcribing DNA into RNA

Answer

Translating RNA into proteins

Question 21

Which type of mutation results in a premature stop codon, potentially leading to a truncated protein product?

Accepted Answer

Nonsense mutation

Answer

Missense mutation

Answer

Silent mutation

Answer

Frameshift mutation

Question 22

During transcription, which enzyme is responsible for bonding nucleotides together to form a new RNA molecule?

Accepted Answer

RNA polymerase

Answer

DNA polymerase

Answer

Ligase

Answer

Helicase

Question 23

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

Accepted Answer

Gel electrophoresis

Answer

Polymerase chain reaction (PCR)

Answer

DNA sequencing

Answer

Southern blotting

Question 24

The process of DNA replication involves using one DNA strand as a template to synthesize a complementary strand. What is this process called?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Mutation

Question 25

Which type of RNA molecule does NOT directly participate in protein synthesis?

Accepted Answer

miRNA

Answer

rRNA

Answer

mRNA

Answer

tRNA

Question 26

Telomeres are specialized structures found at the ends of chromosomes. What is their primary function?

Accepted Answer

Protecting chromosome ends from degradation

Answer

Initiating DNA replication

Answer

Promoting chromosome segregation during cell division

Answer

Regulating gene expression

Question 27

How do mutations contribute to genetic inheritance and evolutionary processes?

Accepted Answer

Mutations increase genetic diversity, driving evolution.

Answer

Mutations primarily repair damaged DNA.

Answer

Mutations always prevent harmful mutations.

Answer

Mutations exclusively enhance gene expression.

Question 28

Which structural component is NOT found in a nucleotide?

Accepted Answer

Amino acid

Answer

Phosphate group

Answer

Nitrogenous base

Answer

Sugar molecule

Question 29

Which process ensures faithful duplication of genetic information during cell division?

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Mutation

Question 30

What is the primary function of RNA polymerase in transcription?

Accepted Answer

To synthesize an RNA molecule complementary to a DNA template

Answer

To unwind the DNA double helix

Answer

To bind specifically to promoter regions on DNA

Answer

To process and modify RNA transcripts

Question 31

Which term best describes the rules that determine the specific amino acid sequence of a protein based on the sequence of nucleotides in a gene?

Accepted Answer

Genetic code

Answer

Transcriptional regulation

Answer

Translation initiation

Answer

Protein folding

Question 32

Which molecules are responsible for carrying amino acids to the ribosome during protein synthesis?

Accepted Answer

Transfer RNA (tRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Messenger RNA (mRNA)

Answer

MicroRNA (miRNA)

Question 33

Which of the following best defines a mutation?

Accepted Answer

A permanent alteration in the DNA sequence

Answer

An error in DNA replication

Answer

A change in gene expression

Answer

A chromosomal rearrangement

Question 34

Which type of mutation involves the insertion or deletion of nucleotides, potentially disrupting the reading frame of a gene?

Accepted Answer

Frameshift mutation

Answer

Missense mutation

Answer

Nonsense mutation

Answer

Silent mutation

Question 35

Which commonly used technique is employed to amplify specific regions of DNA for analysis?

Accepted Answer

Polymerase Chain Reaction (PCR)

Answer

DNA sequencing

Answer

Microarray analysis

Answer

Southern blotting

Question 36

Which of the following is an example of a genetic disorder primarily caused by a mutation in a single gene?

Accepted Answer

Cystic fibrosis

Answer

Heart disease

Answer

Diabetes

Answer

Cancer

Question 37

How do transcription factors regulate gene expression, and what happens when they malfunction?

Accepted Answer

Transcription factors bind to DNA, changing chromatin structure and recruiting RNA polymerase to control gene expression.

Answer

Transcription factors directly interact with RNA polymerase, boosting its efficiency and accuracy.

Answer

Transcription factors mainly regulate gene expression by affecting mRNA stability and translation.

Answer

Transcription factors do not directly regulate gene expression; they primarily control mRNA splicing.

Question 38

Which codon represents the amino acid glycine and consists of three guanine nucleotides?

Accepted Answer

GGG

Answer

GAG

Answer

GGA

Question 39

During DNA replication, which enzyme facilitates the unwinding of the double helix at the replication fork?

Accepted Answer

Helicase

Answer

Ligase

Answer

DNA polymerase

Answer

RNA polymerase

Question 40

Which of the following modifications is a type of DNA methylation commonly found in eukaryotic organisms?

Accepted Answer

5-methylcytosine

Answer

Glycosylation

Answer

Acetylation

Answer

Phosphorylation

Question 41

The process by which genetic information from DNA is used to synthesize a complementary RNA molecule is referred to as:

Accepted Answer

Transcription

Answer

Replication

Answer

Translation

Answer

Splicing

Question 42

In the central dogma of molecular biology, the correct sequence of events for protein synthesis is:

Accepted Answer

Transcription, Translation, Folding

Answer

Transcription, Folding, Translation

Answer

Translation, Transcription, Folding

Answer

Folding, Transcription, Translation

Question 43

Which molecular biology technique is widely used to amplify specific regions of DNA?

Accepted Answer

Polymerase Chain Reaction (PCR)

Answer

Microarray

Answer

DNA sequencing

Answer

Gel electrophoresis

Question 44

The central dogma of molecular biology describes the unidirectional flow of genetic information from:

Accepted Answer

DNA → RNA → Protein

Answer

Protein → DNA → RNA

Answer

Protein → RNA → DNA

Answer

RNA → DNA → Protein

Question 45

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

Accepted Answer

DNA helicase

Answer

Topoisomerase

Answer

DNA polymerase

Answer

DNA ligase

Question 46

A mutation occurs in the gene encoding the enzyme responsible for adding a 5' cap to mRNA. What is the most likely consequence of this mutation?

Accepted Answer

Reduced mRNA stability and translation efficiency.

Answer

Increased mRNA stability and translation efficiency.

Answer

No significant change in mRNA processing.

Answer

Increased likelihood of mRNA degradation.

Question 47

A researcher is studying gene regulation in a bacterial cell. They observe a protein binding upstream of a gene's coding sequence, preventing RNA polymerase from attaching. This protein is most likely a:

Accepted Answer

Repressor

Answer

Enhancer

Answer

Silencer

Answer

Activator

Question 48

Which characteristic is NOT a feature of the genetic code?

Accepted Answer

Ambiguous

Answer

Universal

Answer

Non-overlapping

Answer

Degenerate

Question 49

A protein consists of 150 amino acids. How many nucleotides are needed to encode this protein?

Accepted Answer

450

Answer

600

Answer

300

Answer

150

Question 50

During translation, the tRNA carrying the next amino acid to be added to the growing polypeptide chain binds to which site on the ribosome?

Accepted Answer

A site

Answer

R site

Answer

E site

Answer

P site

Question 51

What is a key difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

Prokaryotic mRNA is often polycistronic, while eukaryotic mRNA is typically monocistronic.

Answer

Prokaryotes lack a nucleus, while eukaryotes have a nucleus.

Answer

Prokaryotic transcription and translation occur simultaneously, while eukaryotic transcription and translation are separated.

Question 52

A frameshift mutation occurs when:

Accepted Answer

A nucleotide is inserted or deleted, shifting the reading frame of the gene.

Answer

A single nucleotide is substituted with another.

Answer

A large segment of DNA is duplicated.

Question 53

A patient has a rare genetic disorder caused by a defect in the enzyme that repairs DNA damage from ultraviolet radiation. This enzyme is most likely:

Accepted Answer

Photolyase

Answer

Telomerase

Answer

DNA polymerase

Answer

DNA ligase

Question 54

During DNA replication, a segment of DNA is being replicated discontinuously. This is because:

Accepted Answer

The lagging strand is synthesized in fragments.

Answer

DNA polymerase cannot initiate replication.

Answer

The leading strand is synthesized in fragments.