AP BIOLOGY

Detailed explanation-1: -One dominant allele (F) is sufficient for its trait (has freckles) to be observable, but both alleles have to be recessive (f) for the recessive trait (no freckles) to be observable. In one of the genes that determines hair color, red hair is recessive to brown hair.

Detailed explanation-2: -Freckles are dominant (F) and no freckles is recessive (f). Two parents both have freckles.

Detailed explanation-3: -Freckles are small, concentrated irregularly shaped spots of skin pigments called melanin. Freckles are dominant (F) and primarily controlled by the MC1R gene. A person that is heterozygous for freckles would have a phenotype that shows freckles on their skin and possess the genotype Ff.

Detailed explanation-4: -Whether or not you have freckles depends on the combination of the freckle (F) and non-freckle (f) versions of MC1R you have. Both FF and Ff people have freckles. What this means is that anyone with at least one copy of the freckle version (F) will have freckles. This is why having freckles is a dominant trait.

Detailed explanation-5: -It is caused by inheriting two recessive alleles (ff). People who have the heterozygous genotype (Ff) are said to be carriers, with no ill effects. Only people who have the homozygous (ff) are affected. The recessive allele must be inherited from both parents.