Codon Reading: Contiguous & No Punctuation — NEET Biology

The genetic code is read continuously on mRNA without any gaps, spaces, or punctuation marks between codons. This means ribosomes read codons sequentially (AUG-UUC-GUA...) without pausing between them. Students often mistakenly think there are separators or overlapping regions between codons, leading to incorrect interpretation of protein synthesis. NTA tests this by asking how codons are identified or what happens if the reading frame shifts. Remember: codons are adjacent three-nucleotide units with no interruptions—this is why a single nucleotide insertion or deletion causes a frameshift mutation affecting the entire downstream sequence.