Question

Any two of you typically have an estimated 0.1% difference in your nucleotide sequences, which is equivalent to about 3 million nucleotide differences (3 billion base pairs in the human genome). These differences are the basis of the SNPs used to construct genetic linkage maps. Some of these SNPs actually lie in the region of the DNA that codes for the protein, yet they have no effect on the phenotype of individuals carrying the SNP on both homologous chromosomes. Of the following answer which is the most probable??

A) In all cases they code for the same amino acid., and that is why these are tolerated.
B) The wobble nature of the genetic code can tolerate these differences.
C) Amino acid substitutions in some cases will happen but they will still permit the eventual protein to function.
D) There are always other duplicate genes which can substitute for their defective copies.
E) None of the above.

Answer 1

The correct answer is option B.

Step-by-step explanation:

The SNPs or the single nucleotide polymorphisms refers to the most general kind of genetic variation. Each of the SNP demonstrates a difference in a single building block of DNA known as a nucleotide.

In total, there are sixty-four codons that codes for twenty different amino acids and three stop codons. The synonymous SNP does not modify the sequence of amino acids of the protein. GUU, GUA, GUC, and GUG all these codons differ at third position, however, they all code for the similar amino acid, that is, valine.

Therefore, these differences, that is, the synonymous mutation could be accepted as they result in no change to the primary sequence of amino acids of the protein.