Pleotropic character represent that quality of gene which is called

$A$ : $SNPs$-pronounced "snips" are common in human genome.
$R$ : It is minute variations that occurs at a frequency of one in every $300$ bases

Cri­-du-­chat syndrome in humans is caused by the

Which one of the following correctly represents the manner of replication of $DNA$

If in a test tube, $mRNA$ of E. coli cells and $tRNAs$ from the body of rats are taken and sufficient number of amino acids are put, then the polypeptide synthesized will be of the nature of