AP BIOLOGY

Detailed explanation-1: -If someone possesses both the dominant and recessive alleles for tongue rolling, we would write his or her genotype as “Rr”. The capital R shows that there is one dominant allele for tongue rolling, and the lower case r represents the other, recessive allele.

Detailed explanation-2: -If two heterozygous parents have children then the possible outcomes are shown below. Here we have a 25% chance that a non-roller is born. This example shows how a recessive trait, hidden in the parents, can become visible in their offspring.

Detailed explanation-3: -The ability to roll tongue is dominant over inability to do it. If the dominant allele is R and the recessive allele is r, therefore the two individuals have the homozygous recessive character. This means the genotype of the organism will be ‘rr’.

Detailed explanation-4: -In other words, if you inherited one or two copies of the dominant “tongue rolling gene” (R) allele from your parents, then you would be able to roll your tongue. If you inherited two copies of the recessive “tongue rolling gene” (r) allele instead, then you would not be able to roll your tongue.