Codons are base "words" that code for specific amino acids. they are and never the words.

Codons are 3 base "words" that code for specific amino acids. They are non-overlapping and never have gaps between the word

Ans.

During protein synthesis, the information for protein synthesis is present in the DNA, is transferred to mRNA, by the process of transcription. In mRNA this information is present in the form of triplet nucleotides, called as codons or genetic codes.

Each genetic code for a particular amino acid and helps in synthesis of protein molecules during translation. The genetic codes are non-overlapping and they form a open reading frame. There is no gap present between the codons and they form a successive open reading frame.

Thus, the correct words to be filled in the first, second and third blank are 'three,' non-overlapping', and 'show gap between,' respectively.

substitution is the answer in this case