Gene Structure and Expression: A Comprehensive Guide for Medical Students

Question 1

Which codon corresponds to the amino acid glycine?

Accepted Answer

GGA

Answer

UGU

Answer

AUG

Answer

CCC

Question 2

Which of the following is NOT a function of transcription factors?

Accepted Answer

Translating mRNA into protein

Answer

Binding to specific DNA sequences

Answer

Recruiting RNA polymerase to the promoter

Answer

Modifying chromatin structure

Question 3

Which component is **not** found in a nucleotide?

Accepted Answer

Amino acid

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Nitrogenous base

Question 4

What is the primary role of RNA polymerase in gene expression?

Accepted Answer

To synthesize a complementary RNA strand

Answer

To unwind the DNA double helix

Answer

To modify the pre-mRNA transcript

Answer

To transport the mRNA to the cytoplasm

Question 5

Which feature of the genetic code contributes to its redundancy?

Accepted Answer

Multiple codons can code for the same amino acid.

Answer

A single codon can code for multiple amino acids.

Answer

The genetic code is identical in all organisms.

Answer

The genetic code is non-overlapping.

Question 6

What is the main function of introns in eukaryotic genes?

Accepted Answer

To enable RNA splicing

Answer

To code for protein sequences

Answer

To regulate gene expression

Answer

To enhance gene stability

Question 7

What is the significance of the Shine-Dalgarno sequence in bacterial gene expression?

Accepted Answer

It assists the ribosome in locating the start codon for translation initiation.

Answer

It regulates the rate of transcription.

Answer

It determines the reading frame for translation.

Answer

It protects the mRNA from degradation.

Question 8

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

Accepted Answer

To recruit RNA polymerase for transcription initiation

Answer

To determine the direction of transcription

Answer

To terminate transcription

Answer

To enhance the rate of translation

Question 9

Which of the following is a mechanism for regulating gene expression primarily at the translational level?

Accepted Answer

MicroRNAs (miRNAs)

Answer

Protein phosphorylation

Answer

Alternative splicing

Answer

DNA methylation

Question 10

What is one significant implication of the universality of the genetic code?

Accepted Answer

It facilitates the exchange of genetic information between different organisms.

Answer

It ensures that all proteins are folded correctly in all organisms.

Answer

It prevents the accumulation of harmful mutations.

Answer

It regulates gene expression in all organisms.

Question 11

What is the primary structural component of chromosomes, which carries genetic information?

Accepted Answer

DNA

Answer

Protein

Answer

RNA

Answer

Lipid

Question 12

Identify the enzyme responsible for unwinding the DNA helix during the initiation of transcription.

Accepted Answer

DNA helicase

Answer

RNA polymerase

Answer

Topoisomerase

Answer

Ligase

Question 13

Which type of RNA molecule is responsible for carrying the genetic code from the nucleus to the ribosome?

Accepted Answer

Messenger RNA (mRNA)

Answer

Transfer RNA (tRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Small nuclear RNA (snRNA)

Question 14

What is the role of introns in eukaryotic genes?

Accepted Answer

Removal during RNA splicing

Answer

Coding for protein sequences

Answer

Essential for gene regulation

Answer

Protection from mutation

Question 15

What is the process known as when genetic information is copied from RNA into DNA?

Accepted Answer

Reverse transcription

Answer

Transcription

Answer

Translation

Answer

Replication

Question 16

Which technique is used for amplifying DNA sequences?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

DNA sequencing

Answer

Southern blotting

Answer

Gel electrophoresis

Question 17

What is the genetic code that translates the sequence of nucleotides in mRNA into the sequence of amino acids in a protein?

Accepted Answer

Codon table

Answer

Genetic alphabet

Answer

Anticodon table

Answer

Transcription code

Question 18

Which of the following is a potential application of gene therapy?

Accepted Answer

Treating genetic disorders by introducing functional genes into patients' cells

Answer

Predicting the likelihood of developing genetic diseases based on an individual's genetic makeup

Answer

Identifying individuals who carry genetic diseases without expressing symptoms

Answer

Establishing the paternity of a child through genetic analysis

Question 19

Which mutation type alters the reading frame of a translated protein?

Accepted Answer

Frameshift mutation

Answer

Missense mutation

Answer

Nonsense mutation

Answer

Silent mutation

Question 20

Which region of a gene is responsible for initiating RNA polymerase binding?

Accepted Answer

Promoter

Answer

Intron

Answer

Exon

Answer

Terminator

Question 21

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

Accepted Answer

Messenger RNA (mRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Transfer RNA (tRNA)

Answer

Small nuclear RNA (snRNA)

Question 22

Which of the following is NOT a stage in the process of translation?

Accepted Answer

Maturation

Answer

Initiation

Answer

Elongation

Answer

Termination

Question 23

What is the term for the process of removing introns and joining exons in a newly synthesized RNA molecule?

Accepted Answer

Splicing

Answer

Translation

Answer

Transcription

Answer

Replication

Question 24

Which of the following serves as a mechanism for regulating gene expression by modifying DNA structure?

Accepted Answer

Epigenetic modifications

Answer

microRNA interference

Answer

Alternative splicing

Answer

Phosphorylation

Question 25

What type of mutation results in a premature stop codon within a gene's coding sequence?

Accepted Answer

Nonsense mutation

Answer

Missense mutation

Answer

Silent mutation

Answer

Splice site mutation

Question 26

Which enzyme facilitates the unwinding of the DNA double helix during transcription?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

RNA polymerase

Answer

Exonuclease

Question 27

How is gene expression linked to the development of genetic disorders?

Accepted Answer

Altered gene expression can contribute to genetic disorders

Answer

Gene expression has no role in the development of genetic disorders

Answer

Genetic disorders solely result from mutations in DNA

Answer

Gene expression affects only disorders passed down through families

Question 28

Which of the following correctly describes the sequential steps in gene expression?

Accepted Answer

Transcription, RNA processing, translation

Answer

Translation, transcription, RNA processing

Answer

RNA processing, transcription, translation

Answer

Transcription, translation, RNA processing

Question 29

The promoter region of a gene contains sequences that primarily:

Accepted Answer

Signal the start of transcription

Answer

Encode the protein product of the gene

Answer

Regulate the expression of the gene

Answer

Terminate transcription

Question 30

The genetic code is based on:

Accepted Answer

Triplets of nucleotides

Answer

Quadruplets of nucleotides

Answer

Quintuplets of nucleotides

Answer

Hexaplets of nucleotides

Question 31

Which cellular structure is responsible for catalyzing the formation of peptide bonds during translation?

Accepted Answer

Ribosome

Answer

RNA polymerase

Answer

Aminoacyl tRNA synthetase

Answer

Helicase

Question 32

Which technique is commonly used to study gene expression patterns?

Accepted Answer

Microarray analysis

Answer

Polymerase chain reaction

Answer

Gel electrophoresis

Answer

Western blotting

Question 33

The Human Genome Project was officially completed in:

Accepted Answer

2003

Answer

1999

Answer

2006

Answer

2010

Question 34

The comprehensive study of gene expression patterns in different tissues and cell types is referred to as:

Accepted Answer

Transcriptomics

Answer

Proteomics

Answer

Metabolomics

Answer

Genomics

Question 35

Which process involves the synthesis of proteins from an RNA template?

Accepted Answer

Translation

Answer

Transcription

Answer

Replication

Answer

Condensation

Question 36

What is the technique known for amplifying specific DNA sequences?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Gel electrophoresis

Answer

Southern blotting

Answer

DNA sequencing

Question 37

What is a characteristic of a dominant allele?

Accepted Answer

Expressed in both homozygous and heterozygous individuals

Answer

Requires two copies for expression

Answer

Only expressed in homozygous individuals

Answer

Has no phenotypic effect

Question 38

What is the main function of the spliceosome in RNA processing?

Accepted Answer

Removing introns from the RNA transcript

Answer

Adding methyl groups to the RNA transcript

Answer

Polyadenylating the RNA transcript

Answer

Cleaving the RNA transcript into separate mRNA molecules

Question 39

State the central dogma of molecular biology.

Accepted Answer

Proteins are synthesized from RNA, which is synthesized from DNA

Answer

RNA is synthesized from proteins, which is synthesized from DNA

Answer

DNA is synthesized from proteins, which is synthesized from RNA

Answer

DNA is synthesized from RNA, which is synthesized from proteins

Question 40

How do epigenetic modifications affect gene expression?

Accepted Answer

Epigenetic modifications can change the structure of chromatin, making genes more or less accessible for transcription.

Answer

Epigenetic modifications alter the DNA sequence, changing the genetic code.

Answer

Epigenetic modifications are always inherited from parents to offspring.

Question 41

Which of the following correctly describes the sequential order of events in gene expression?

Accepted Answer

Transcription initiates the synthesis of RNA from DNA, followed by translation, which uses RNA to synthesize proteins.

Answer

Transcription occurs after translation, which is then followed by the initiation of protein synthesis.

Answer

Translation initiates the synthesis of proteins from RNA, followed by transcription, which uses DNA to synthesize RNA.

Question 42

What is the primary role of the promoter region in a gene?

Accepted Answer

Binds RNA polymerase and initiates transcription.

Answer

Encodes the termination signal for transcription.

Answer

Contains the coding sequence for the protein that the gene encodes.

Answer

Provides a binding site for regulatory proteins that control gene expression.

Question 43

What is the main purpose of introns within eukaryotic genes?

Accepted Answer

Removed during RNA splicing, allowing for the production of different protein isoforms.

Answer

Code for a specific protein sequence that is required for gene function.

Answer

Enhance gene expression by increasing the rate of transcription.

Answer

Bind to ribosomes during translation to facilitate the synthesis of proteins.

Question 44

What is the primary function of histones in regulating gene expression?

Accepted Answer

Associate with DNA to form chromatin, influencing the accessibility of genes to transcriptional machinery and regulating gene activity.

Answer

Translate mRNA into a sequence of amino acids to form proteins.

Answer

Initiate transcription by binding to the promoter region of genes.

Question 45

What is the term for the process by which genes are turned off or their expression is reduced?

Accepted Answer

Gene silencing

Answer

Gene regulation

Answer

Gene activation

Answer

Gene amplification

Question 46

Which of the following is a primary advantage of using MCQs in assessments?

Accepted Answer

Provides objective and standardized scoring, reducing bias and ensuring consistency in evaluation.

Answer

Provides extensive feedback on student responses, identifying areas for improvement.

Answer

Allows students to demonstrate their creative thinking and problem-solving skills.

Answer

Eliminates the need for instructors to manually grade student responses, saving time and effort.

Question 47

What is the primary role of RNA polymerase in gene expression?

Accepted Answer

Synthesizes RNA using a DNA template during transcription.

Answer

Initiates protein synthesis.

Answer

Breaks down DNA into individual nucleotides.

Answer

Transports mRNA to the ribosome.

Question 48

In what order do the stages of translation occur?

Accepted Answer

Initiation, elongation, termination.

Answer

Elongation, termination, initiation.

Answer

Termination, elongation, initiation.

Answer

Initiation, termination, elongation.

Question 49

What is the main function of a transcription factor in gene expression?

Accepted Answer

Binds to specific DNA sequences to regulate the transcription of genes.

Answer

Splices introns from pre-mRNA.

Answer

Protects DNA from degradation.

Question 50

What is the primary consequence of a missense mutation?

Accepted Answer

A change in the amino acid sequence of a protein.

Answer

A premature stop codon.

Answer

A frameshift mutation.

Answer

A silent mutation.

Question 51

What is the fundamental purpose of the genetic code?

Accepted Answer

To translate the sequence of nucleotides in DNA or RNA into the sequence of amino acids in a protein.

Answer

To regulate gene expression.

Answer

To store genetic information in a compact form.

Question 52

Which of the following accurately describes a eukaryotic ribosome?

Accepted Answer

It is composed of two subunits, a large subunit and a small subunit.

Answer

It is located in the nucleus.

Answer

It is responsible for synthesizing DNA.

Question 53

What is the distinction between a codon and an anticodon?

Accepted Answer

A codon is a three-nucleotide sequence in mRNA, while an anticodon is a three-nucleotide sequence in tRNA.

Answer

A codon signals the start of translation, while an anticodon signals the end of translation.