Biology

Molecular Genetics

851 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 a start codon?

  1. A codon that codes for an amino acid.

  2. A codon that codes for a stop signal.

  3. A codon that codes for a start signal.

  4. A codon that codes for a regulatory element.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A start codon is a codon that codes for a start signal. Start signals are used to initiate protein synthesis.

Multiple choice

What is the role of tRNA in protein synthesis?

  1. It carries amino acids to the ribosome.

  2. It reads the mRNA sequence.

  3. It synthesizes the protein chain.

  4. It releases the protein from the ribosome.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

tRNA carries amino acids to the ribosome. Each tRNA molecule is specific for a particular amino acid.

Multiple choice

What is the role of mRNA in protein synthesis?

  1. It carries genetic information from DNA to the ribosome.

  2. It is translated into protein.

  3. It regulates gene expression.

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

mRNA carries genetic information from DNA to the ribosome, is translated into protein, and regulates gene expression. It is a versatile molecule that plays a key role in protein synthesis.

Multiple choice

What is the role of the ribosome in protein synthesis?

  1. It reads the mRNA sequence.

  2. It synthesizes the protein chain.

  3. It releases the protein from the ribosome.

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

The ribosome reads the mRNA sequence, synthesizes the protein chain, and releases the protein from the ribosome. It is a complex molecular machine that is essential for protein synthesis.

Multiple choice

The molecule that carries genetic information in all living organisms is:

  1. DNA

  2. RNA

  3. Protein

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

DNA (deoxyribonucleic acid) is the molecule that carries genetic information in all living organisms. It is a double-stranded molecule composed of four different types of nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).

Multiple choice

The process by which DNA is copied into RNA is called:

  1. Replication

  2. Transcription

  3. Translation

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

Transcription is the process by which DNA is copied into RNA. It is carried out by an enzyme called RNA polymerase, which reads the DNA sequence and synthesizes a complementary RNA molecule.

Multiple choice

The process by which RNA is used to synthesize proteins is called:

  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 RNA is used to synthesize proteins. It is carried out by ribosomes, which read the RNA sequence and assemble the corresponding amino acids into a protein chain.

Multiple choice

The process by which cells repair damaged DNA is called:

  1. Replication

  2. Transcription

  3. Translation

  4. DNA repair
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

DNA repair is the process by which cells repair damaged DNA. It is carried out by a variety of enzymes, which can repair different types of DNA damage.

Multiple choice

What is the central dogma of molecular biology?

  1. DNA makes RNA makes protein

  2. RNA makes DNA makes protein

  3. Protein makes DNA makes RNA

  4. DNA makes protein makes RNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The central dogma of molecular biology states that the information in DNA is transcribed into RNA, which is then translated into protein.

Multiple choice

Which of the following is NOT a type of RNA?

  1. mRNA

  2. tRNA

  3. rRNA

  4. snRNA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

snRNA is a type of small nuclear RNA, which is involved in the processing of RNA transcripts.

Multiple choice

What is the function of a promoter in gene expression?

  1. To bind RNA polymerase and initiate transcription

  2. To terminate transcription

  3. To splice introns out of RNA transcripts

  4. To polyadenylate RNA transcripts
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.