Answer:
The start and stop codons —part of the mRNA's genetic code— are necessary because they indicate the exact length a protein should have.
Step-by-step explanation:
The sequence of bases contained in an mRNA strand is the genetic code that allows the synthesis of specific proteins. The mRNA information is organized into triplets or codons, whose function is :
- To code the amino acids that will be incorporated into the protein to be synthesized.
- To establish the sequence of amino acids of a peptide or protein, which depends on the sequence of codons formed by nitrogenous bases.
- To mark the beginning of the synthesis, with the starting codon that, in addition, codes the amino acid Methionine.
- Establish the end of the synthesis, through the three stop codons, UAA, UAG and UGA.
The importance of the start and stop codons is that they establish the exact length that, genetically established, a specific protein must have.