Question

Identify all the amino acid–specifying codons in the genetic code where a point mutation (a single base change) could generate a nonsense codon.

A) UAA
B) AUG
C) UAC
D) GCA
1.A and B
2.B and C
3.C only
4.D only

Answer 1

The amino acid-specifying codons in the genetic code where a point mutation could generate a nonsense codon are UAA, UAG, and UGA.

Step-by-step explanation:

The amino acid-specifying codons in the genetic code where a point mutation could generate a nonsense codon are UAA, UAG, and UGA. These codons are also known as stop codons or termination codons because they signal the end of protein synthesis.

In the given options, only option A (UAA) is a stop codon, so the correct answer is 4. D only.