Biology

Molecular Genetics

917 Questions

Molecular genetics explores the mechanisms of genetic information transfer, including DNA replication, transcription, and translation. It is a core component of biology syllabi. These concepts frequently appear in general science sections of major competitive exams.

DNA replicationTranscription processTranslation processRNA typesCentral dogma

Molecular Genetics Questions

Multiple choice

What is the process by which RNA is converted into protein?

  1. Replication

  2. Transcription

  3. Translation

  4. Mutation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Translation is the process by which the information encoded in RNA is used to synthesize a protein, converting the genetic code into a functional molecule.

Multiple choice

What is the genetic code?

  1. A set of rules that determines how DNA is replicated.

  2. A set of rules that determines how RNA is transcribed.

  3. A set of rules that determines how RNA is translated into protein.

  4. A set of rules that determines how proteins are folded into their functional shapes.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The genetic code is a set of rules that determines how the sequence of nucleotides in RNA is translated into a sequence of amino acids in a protein.

Multiple choice

What is the role of RNA polymerase in transcription?

  1. It unwinds the DNA double helix.

  2. It synthesizes new RNA strands.

  3. It proofreads the newly synthesized RNA strands.

  4. It separates the two DNA strands.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

RNA polymerase is the enzyme responsible for synthesizing new RNA strands during transcription, adding nucleotides to the growing RNA chain in a template-directed manner.

Multiple choice

What is the role of ribosomes in translation?

  1. They unwind the mRNA molecule.

  2. They synthesize new proteins.

  3. They proofread the newly synthesized proteins.

  4. They separate the two mRNA strands.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ribosomes are the cellular structures responsible for synthesizing new proteins during translation, reading the mRNA sequence and assembling amino acids in the correct order to form a polypeptide chain.

Multiple choice

What is the central dogma of molecular biology?

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

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

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

  4. Protein is transcribed into RNA, which is then translated into DNA.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The central dogma of molecular biology describes the flow of genetic information from DNA to RNA to protein, providing the fundamental framework for understanding gene expression and protein synthesis.

Multiple choice

What is the role of introns and exons in gene expression?

  1. Introns are transcribed into RNA and exons are translated into protein.

  2. Introns are translated into protein and exons are transcribed into RNA.

  3. Introns are spliced out of RNA before translation and exons are translated into protein.

  4. Introns are spliced out of DNA before transcription and exons are transcribed into RNA.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Introns are non-coding regions of DNA that are removed from the RNA transcript through a process called splicing, while exons are coding regions that remain in the RNA transcript and are translated into protein.

Multiple choice

Which of the following is an example of a protein that regulates gene expression?

  1. Transcription factors

  2. Repressors

  3. Activators

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transcription factors, repressors, and activators are all proteins that regulate gene expression.

Multiple choice

What is the role of a promoter in gene expression?

  1. It binds RNA polymerase

  2. It enhances the expression of the gene

  3. It terminates transcription

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A promoter is a region of DNA that binds RNA polymerase and initiates transcription.

Multiple choice

What is the role of a terminator in gene expression?

  1. It binds RNA polymerase

  2. It enhances the expression of the gene

  3. It terminates transcription

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A terminator is a region of DNA that signals the end of transcription.

Multiple choice

What is the role of an enhancer in gene expression?

  1. It binds RNA polymerase

  2. It enhances the expression of the gene

  3. It terminates transcription

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An enhancer is a region of DNA that enhances the expression of a gene.

Multiple choice

What is the process by which DNA is copied into RNA?

  1. Transcription

  2. Translation

  3. Replication

  4. Mutation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Transcription is the process by which DNA is copied into RNA. This process is carried out by RNA polymerase, which binds to the DNA and separates the two strands. The RNA polymerase then uses one of the DNA strands as a template to synthesize a complementary RNA strand.

Multiple choice

What is the process by which RNA is used to synthesize proteins?

  1. Transcription

  2. Translation

  3. Replication

  4. Mutation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Translation is the process by which RNA is used to synthesize proteins. This process is carried out by ribosomes, which bind to the RNA and read the sequence of codons. Each codon corresponds to a specific amino acid, and the ribosome uses this information to assemble a chain of amino acids into a protein.

Multiple choice

What is a gene?

  1. A region of DNA that codes for a protein

  2. A region of RNA that codes for a protein

  3. A region of DNA that codes for a non-coding RNA

  4. A region of RNA that codes for a non-coding RNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A gene is a region of DNA that codes for a protein. Genes are made up of a series of codons, which are sequences of three nucleotides that correspond to specific amino acids. The sequence of codons in a gene determines the sequence of amino acids in the protein that it codes for.

Multiple choice

What is the central dogma of molecular biology?

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

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

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

  4. Protein is transcribed into RNA, which is then translated into DNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The central dogma of molecular biology is the idea that DNA is transcribed into RNA, which is then translated into protein. This process is essential for the synthesis of proteins, which are the building blocks of cells.

Multiple choice

What is the role of RNA polymerase in transcription?

  1. It binds to the DNA and separates the two strands

  2. It uses one of the DNA strands as a template to synthesize a complementary RNA strand

  3. It proofreads the RNA strand for errors

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

RNA polymerase is an enzyme that plays a key role in transcription. It binds to the DNA and separates the two strands. It then uses one of the DNA strands as a template to synthesize a complementary RNA strand. RNA polymerase also proofreads the RNA strand for errors.