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 antisense technology?

  1. RNA polymerase producing DNA.

  2. A cell displaying a foreign antigen used for synthesis of antibodies.

  3. Production of somaclonal variants in tissue cultures.

  4. When a piece of RNA that is complementary in sequence is used to stop expression of a specific gene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Antisense technology is the translational control of protein synthesis which involves use of RNA which is complementry to m-RNA, inhibiting the expression of genes.

Multiple choice

RNA retroviruses have special enzyme that

  1. transcribes viral RNA to DNA

  2. disintegrates host DNA

  3. translates host DNA

  4. polymerises host DNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

RNA retroviruses have special enzyme that transcribes viral RNA to DNA. 

Multiple choice

Assertion: In capping, methyl guanosine triphosphate is added to the 3'-end of hnRNA. Reason: In tailing, adenylate residues are added at 5'-end in a template independent manner.

Direction: In the following question there are two statements, Assertion (A) and Reason (R), consider both the statements independently and mark your answers as under:

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

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

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

Both are incorrect statements. In capping, methyl guanosine triphosphate is added to the 5'-end of hnRNA. In tailing, adenylate residues are added at 3'-end in a template independent manner. It is the fully processed hnRNA, now called mRNA, that is transported out of the nucleus for translation.

Multiple choice

Where is rDNA multiplied?

  1. In target vector

  2. In cloning vector

  3. In viruses

  4. In archaebacteria

  5. In eukaryotic protista
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cloning vector is just for making many similar copies of desired gene DNA.

Multiple choice

Which of the following statements are FALSE?

  1. Coding of information from DNA to mRNA is transcription.
  2. RNA polymerase produce RNA strand in 3’ → 5’ direction only.
  3. Turner’s syndrome results due to trisomy of ’X’ chromosome.
  4. DNA synthesis takes place during S phase.

  1. 1 and 2

  2. 1 and 4

  3. 2 and 3

  4. 2 and 4

  5. 3 and 4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Correct answer. Both are false statements. RNA polymerase produce RNA strand in 5’ → 3’ direction only. Turner’s syndrome results due to monosomy of ’X’ chromosome.

Multiple choice

Which among the following is a large class of self-catalytic ribozymes?

  1. Group I introns

  2. Group II introns

  3. Twintrons

  4. LtrA

  5. Spliceosome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Group II introns is a large class of self-catalytic ribozymes as well as mobile genetic element found within the genes of all three domains of life. Ribozyme activity (e.g., Self-splicing) can occur under high-salt conditions in vitro.

Multiple choice

Which of the following snRNAs recognizes and binds to the sequence of the 5'-splice site of an intron in a strand of pre-mRNA?

  1. U1 spliceosomal RNA

  2. U2 spliceosomal RNA

  3. U4 spliceosomal RNA

  4. U5 spliceosomal RNA

  5. U6 spliceosomal RNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

U1 spliceosomal RNA is the small nuclear RNA (snRNA) component of U1 snRNP (small nuclear ribonucleoprotein). Splicing or the removal of introns, is a major aspect of post-transcriptional modification. The U1 snRNP recognizes and binds to the sequence of the 5'-splice site of an intron in a strand of pre-mRNA.