What would happen if, in a gene encoding a polypeptide of 50 amino acids, the 25 th codon (UAU) is mutated to UAA?
Correct answer: A. A polypeptide of 24 amino acids will be formed.
- A. A polypeptide of 24 amino acids will be formed.
- B. Two polypeptides of 24 and 25 amino acids will be formed.
- C. A polypeptide of 49 amino acids will be formed.
- D. A polypeptide of 25 amino acids will be formed.
Explanation
UGA, UAG and UAA are three non sense (or termination) codons which do not code for any amino acid. If, in a gene encoding a polypeptide of 50 amino acids, the 25th codon is mutated to UAA or any of the termination codons, then the chain will be terminated at that place because it will become difficult for tRNA to bring an amino acid from the amino acid pool. So in that case a polypeptide of 24 amino acids will be formed.
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