Go through the following facts:
I. 'AAG' always code for lysine. It cannot code for any other amino acid.
II. Serine amino acid can be coded by UCU / UCC / UCA or UCG.
III. UUU from phenylalanine in bacteria as well as human beings.
IV. UUU GGG CCC AAA Me codes for five amino acids.
Now point out nature of genetic code after reading above:
(a) 1 – Specificity / Non-ambiguity of code; II - Universality of code; III - Degeneracy of code; IV - Triplet and non-overlapping code
(b) I – Specificity / Non-ambiguity of code; II - Degeneracy of code; III - Universality of code; IV - Triplet and non-overlapping code
(c) 1 – Specificity / Non-ambiguity of code; II - Degeneracy of code; III - Universality of code; IV - Triplet and overlapping code
(d) 1 – Specificity / Non-ambiguity of code; II - Universality of code; III - Degeneracy of code; IV - Triplet and overlapping code

  1. One codon codes for only one amino acid, hence, it is unambiguous and specific
  2. Some amino acids are coded by more than one codon, hence the code is degenerate.
  3. The code is nearly universal: for example, from bacteria to human UUU would code for Phenylalanine (phe). Some exceptions to this rule have been found in mitochondrial codons, and in some protozoans.
  4. Each codon is a triplet and codes for one amino acid. Codons do not overlap and are read sequentially.

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