Observe the table and answer the given question:
How many amino acids have only two codons coding for them each?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 9
The genetic code specifies the following amino acids that each have two codons:
- Phenylalanine (Phe) - UUU, UUC
- Tyrosine (Tyr) - UAU, UAC
- Histidine (His) - CAU, CAC
- Glutamine (Gln) - CAA, CAG
- Asparagine (Asn) - AAU, AAC
- Lysine (Lys) - AAA, AAG
- Aspartic acid (Asp) - GAU, GAC
- Glutamic acid (Glu) - GAA, GAG
- Cysteine (Cys) - UGU, UGC
There are 9 amino acids that have exactly two codons coding for them.
The Codons for the Various Amino Acids