If constitutive sequence of 4 nucleotide codes for 1 amino acid, how many amino acids can be theoretically formed?
Codon -The triplet nucleotide sequence present in the mRNA representing specific amino acid:

If 1 base represent 1 amino acid, only 4 amino acid.
If 2 base represent 1 amino acid, 42 amino acids, i.e. 16 amino acids.
If 3 base represent one amino acid, 43 i.e. 64 amino acids.
If 4 bases represent 1 amino acid, 44 i.e. 256 amino acids.

Reference- Harper 30th edition Pg- 415
4
64
16
256