AP BIOLOGY

Detailed explanation-1: -This type of inheritance is called Mendelian Inheritance. Cleft chin, cheek dimples, face freckles and widow’s peaks are some monogenic traits. The presence of these characteristics is dominant, which means that even if the offspring is heterozygous for that allele, the trait will still express itself physically.

Detailed explanation-2: -Dimples-indentations on the cheeks-tend to occur in families, and this trait is assumed to be inherited. Dimples are usually considered a dominant genetic trait, which means that one copy of the altered gene in each cell is sufficient to cause dimples.

Detailed explanation-3: -Blood type AB in humans, for instance, is not a polygenic trait. Rather, it is a case of codominance. The two alleles for A and B antigens on the red blood cells of blood type AB individuals are dominant and therefore are expressed together.

Detailed explanation-4: -Three examples of polygenic traits in humans are height, skin colour and eye colour. These traits are governed by multiple genes.

Detailed explanation-5: -Definition. A polygenic trait is a characteristic, such as height or skin color, that is influenced by two or more genes. Because multiple genes are involved, polygenic traits do not follow the patterns of Mendelian inheritance.