Let R - can roll tongue; r- cannot roll tongue. Lacking the ability can be inherited only when the parents are both heterozygous or both lack the trait. For example, using a Punnett square, Rr x Rr will give genotype 1 RR:2Rr:1rr and 3 can roll tongue:1 cannot roll tongue phenotypes. If both parents lack the ability, all progeny will also lack the trait. The alleles are assorted and segregated independently.
The process of transcription begins when an enzyme called RNA polymerase (RNA pol) attaches to the template DNA strand and begins to catalyze production of complementary RNA.
