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

Assertion (A): The translation of genetic information implied in mRNA into a protein is catalysed by ribosomes. Reason (R): Each three nucleotide codon is translated into one of twenty naturally occurring amino acids.

  1. A and R both are correct and R is the correct explanation of A.

  2. A and R both are correct and R is not the correct explanation of A.

  3. A is correct and R is incorrect.

  4. A is incorrect and R is correct.

  5. A and R both are incorrect.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct. The translation of genetic information implied in mRNA into a protein is catalysed by ribosomes and each three nucleotide codon is translated into one of twenty naturally occurring amino acids.

Multiple choice

Which of the following nucleic acids is a type of oligomer molecule used in molecular biology to modify gene expression?

  1. Morpholino

  2. Aganirsen

  3. Aptamer

  4. Genomic signature

  5. LY2181308
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct. Morpholino is a type of oligomer molecule used in molecular biology to modify gene expression. Morpholinos block access of other molecules to small (~25 base) specific sequences of the base-pairing surfaces of ribonucleic acid (RNA). Morpholinos are used as research tools for reverse genetics by knocking down gene function.

Multiple choice

The smallest RNA is

  1. r-RNA

  2. m-RNA

  3. t-RNA

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

t - RNA or soluble RNA (s - RNA) are smallest RNA which made up of 73 - 93 nucleotides and their molecular weight ranges between 25,000 - 30,000.

Multiple choice

The site for protein synthesis is

  1. ribosome

  2. DNA

  3. nucleus

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

Ribosome is the site for protein synthesis (translation) in both prokaryotes (70S) and eukaryotes (80S). In eukaryotes, 80S type ribosomes are dispersed in cytoplasm or bind to RER.

Multiple choice

The caps and tails attached to mRNA protects it from

  1. proteases<o:p></o:p>

  2. Ligases<o:p></o:p>

  3. Nucleases and phosphatases<o:p></o:p><p></p>

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

The caps and tails attached to mRNA protects it from  Nucleases and phosphatases of cytoplasm.

Multiple choice

A virion is a/ an

  1. ribosome of virus

  2. infective particle of virus

  3. viral gene

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

A virion is a complete viral particle consisting of RNA or DNA surrounded by a protein shell, constituting the infective form of a virus.

Multiple choice

Viral genes are made of

  1. DNA only

  2. RNA only

  3. either proteins or nucleic acids

  4. either RNA or DNA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Viruses typically store their genetic information encoded in molecules of either DNA or RNA -- either one or the other but not both.