The amino acid chain formed by the codons ACU CCA UCG is (D)Thr-Pro-Ser.
A codon sequence having three DNA or RNA nucleotides corresponds to a particular amino acid or the stop codons for the synthesis of proteins. Each group having three nucleotides encode for a particular amino acid and there are three stop codons which indicate the amino acid chain getting stopped for further elongation.
The four nucleotides A,T,G,C or A,U,G,C for DNA and RNA respectively taken three at a time can form total 64 combinations of which three are stop codons. So the remaining 61 codons encode for amino acids which makes the amino acid code degenerate meaning that there can be more than one three letter codon for a particular amino acid.
The correct option is D. The nucleotide triplet that encodes an amino acid is called codon. Each codon represents one amino acid. In the question given above, ACU represents, Threonine, CCA represent Proline and UCG represent Serine. Thus, the amino acid chain form is Thr - Pro - Ser.
