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Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance1 Mark
MCQ
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: The genetic code is degenerate.
Reason : for a particular amino acid more than one codons can be used.
  • ✓
    Both assertion and reason are true, and reason is the correct explanation of assertion.
  • B
    Both assertion and reason are true, but reason is not the correct explanation of assertion.
  • C
    Assertion is true, but reason is false.
  • D
    Both assertion and reason are false
✓

Answer

Correct option: A.
Both assertion and reason are true, and reason is the correct explanation of assertion.
For a particular amino acid, more than one codons can be used. This phenomenon is described by saying that the code is degenerate. A non $-$ degenerate code would be one where there is one to one relationship between amino acids and the codons, so that $44$ codons out of $64,$ will be useless or nonsense codons. However, there are no nonsense codons. The codons which were earlier called nonsense codons are also known to mean stop signals.

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