LIFE SCIENCE

Detailed explanation-1: -A codon or a code word is defined as a group of bases that specify an amino acid. There is strong evidence, which proves that a sequence of three nucleotides codes for an amino acid in the protein, i.e., the code is a triplet . The four bases of nucleotide i.e, (A, G, C, and U) are used to produce three-base codons.

Detailed explanation-2: -A codon is a DNA or RNA sequence of three nucleotides (a trinucleotide) that forms a unit of genomic information encoding a particular amino acid or signaling the termination of protein synthesis (stop signals). There are 64 different codons: 61 specify amino acids and 3 are used as stop signals.

Detailed explanation-3: -The beauty of the system emerges from the fact that there are 64 possible words but they only need 21 different meanings-20 amino acids plus a stop sign. That creates the first layer of redundancy, since codons can be synonyms.

Detailed explanation-4: -Each three-letter sequence of mRNA nucleotides corresponds to a specific amino acid, or to a stop codon. UGA, UAA, and UAG are stop codons. AUG is the codon for methionine, and is also the start codon.