Biology Class 12 MCQ Molecular Basis Of Inheritance – Chapter 6

Biology Class 12 MCQ Molecular Basis Of Inheritance – Chapter 6 : Do you want to score good marks in your class 12 board examinations, so the only way to make your dreams come true is by doing thorough revision of all the topics that are going to come in your examination. Give mock tests, prepare from sample papers, previous year papers and many more.

In this article, we have provided you with some important questions on Molecular Basis Of Inheritance from biology class 12, so scroll down the page and do practice these questions thoroughly, so that you can score full marks in objective type questions asked in your board examinations.

Biology Class 12 MCQ Molecular Basis Of Inheritance – Chapter 6

Ques 1: The initiation codon is

  • AUG
  • UAA
  • UAG
  • UGA


Ques 2: The terminator codon is

  • UAA
  • UAG
  • UGA
  • All of these

All of these

Ques 3: Who proposed Operon hypothesis for the regulation of gene action ?

  • Meselson and Stahl
  • Hershey and Chase
  • Jacob and Monod
  • Nirenberg and Khorana

Jacob and Monod

Ques 4: Each nucleotide, in DNA molecule, is linked to the next by

  • lycosidic bond
  • phosphodiester bond
  • hydrogen bond
  • electrostatic bond

phosphodiester bond

Ques 5: The two polynucleotide chains of DNA molecule w.rt. bases are

  • identical
  • complementary to each other
  • varibale
  • None of these

complementary to each other

Ques 6: The two polynucleotide chains of DNA molecule are spirally coiled to form a double helix. The helix is generally

  • right handed
  • left handed
  • at place right handed and at other places left handed
  • None of these

right handed

Ques 7: The transcribed hnRNA is to be processed which involves

  • capping
  • tailing
  • splicing
  • All of these

All of these

Ques 8: Splicing involves

  • addition of a methyl guanosine triphosphate
  • addition of poly A tail
  • removal of introns through cutting and joining the exons in a defined order
  • All of these

removal of introns through cutting and joining the exons in a defined order

Ques 9: Following RNA(s) are involved in protein synthesis?

  • mRNA
  • tRNA
  • rRNA
  • All of these

All of these

Ques 10: Protein synthesis starts with the

  • activation of amino acids
  • activation of ribosomes
  • charging of tRNA
  • None of the above

activation of amino acids

Ques 11: One gene one enzyme hypothesis was given by

  • Meselson and Stahl
  • Jacob and Mood
  • Beadle and Tatum
  • Watson and Crick

Beadle and Tatum

Ques 12: Structural genes are termed

  • mutons
  • introns
  • recons
  • citrons


Ques 13: Which of teh following enzymes can polymerise the deoxyribonucleotides in 5′-3′ direction during DNA replication ?

  • DNA ligase
  • DNA polymerase
  • Topoisomerase
  • Nuclease

DNA polymerase

Ques 14: The abnormal regions of DNA resulting from mutations are cleaved by which enzymes.

  • Nucleases
  • DNA polymerases
  • RNA polymerases
  • DNA ligases


Ques 15: A triplet base on mRNA chain is called

  • anticodon
  • codon
  • both (a) and (b)
  • neither (a) nor (b)


Ques 16: Which step in transcription is catalyzed by RNA polymerase ?

  • Termination
  • Initiation
  • Elongation
  • All of these


Ques 17: Which of the following human chromosomes was the last to be completely sequenced ?

  • Chromosome X
  • Chromosome II
  • Chromosome 21
  • Chromosome I

Chromosome I

Ques 18: Which is not a part of a transcription unit in DNA?

  • Promoter
  • Inducer
  • Terminator
  • Structural gene


Ques 19: The number of codons that code 20 different amino acids is

  • 64
  • 61
  • 60
  • 32


Ques 20: A nucleoside differs from a nucleotide in not having

  • sugar
  • Phosphate group
  • Nitrogen base
  • glucose

Phosphate group

Physics 12 Current Electricity MCQ Practice Click Here
Biology 12 Principles Of Inheritance And Variation MCQs Click Here
Biology Class 12 MCQs On Human Reproduction Click Here
Biology 12 Reproductive Health MCQ  Click Here

We hope that you have practiced these questions on Molecular Basis Of Inheritance, and you will be feeling more confident about the objective part of this chapter. Our ultimate aim is to help you gain good marks in your board examinations, so keep on practicing. For more mock tests, stay in touch with the page.

Updated: November 18, 2022 — 7:44 am

Leave a Reply

Your email address will not be published.