Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

The codons for the various amino acids are given below. Answer the question.

Identify the degenerate codon from the following:

Options:

CCU, CAU, CGU

UUG, UCG, UAG

AUU, ACU, AAU

GUU, GUG, GUA

Correct Answer:

GUU, GUG, GUA

Explanation:

The correct answer is Option (4) → GUU, GUG, GUA

A degenerate codon refers to codons that code for the same amino acid. In the genetic code, multiple codons can code for a single amino acid, which is known as codon degeneracy.

Analysis of the options:

CCU, CAU, CGU:

    • CCU codes for proline.
    • CAU codes for histidine.
    • CGU codes for arginine.
    • These codons do not code for the same amino acid, so this is not a degenerate set.

UUG, UCG, UAG:

    • UUG codes for leucine.
    • UCG codes for serine.
    • UAG is a stop codon.
    • These codons code for different things, so this is not a degenerate set.

AUU, ACU, AAU:

    • AUU codes for isoleucine.
    • ACU codes for threonine.
    • AAU codes for asparagine.
    • These codons code for different amino acids, so this is not a degenerate set.

GUU, GUG, GUA:

    • All three codons (GUU, GUG, GUA) code for valine.
    • This is an example of a degenerate set because multiple codons code for the same amino acid.