AP BIOLOGY

Detailed explanation-1: -The tongue rolling ability occurs due to the influence of a dominant allele of the gene. A person who has either one or two copies of the dominant allele will be able to twist their tongue. In the case that a person is born with two recessive alleles, they cannot twist their tongue.

Detailed explanation-2: -Tongue rolling, the ability to shape the tongue into a longitudinal trough, is a trait that is commonly used in the classroom as an example of human inheritance. This polymorphic trait is easily determined and its mode of inheritance is presumed to be simple.

Detailed explanation-3: -Some people can roll their tongue and this is a genetically controlled autosomal dominant character. [Roller = RR / Rr and Non-roller = rr]

Detailed explanation-4: -The ability to roll the tongue, and blood groups, are examples of discontinuous variation.

Detailed explanation-5: -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.