AP BIOLOGY

Detailed explanation-1: -Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers. In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers? *A: 0%

Detailed explanation-2: -Chickens have four basic types of feathers-contour, plumules, filoplumes and bristles. Individual feathers can be broken down into specific parts. The shaft runs the length of the feather with the hollow quill at the end that connects to the body.

Detailed explanation-3: -Body hair color is a qualitative trait that is regulated by one or several pairs of genes or alleles. Inheritance of the color of feathers in chickens is influenced by genotype I which carries the color of white feathers, which are dominant and genotype ii which carries the color of feathers which are recessive.

Detailed explanation-4: -Feather color in chickens is a trait that shows incomplete dominance with an allele for black feathers and an allele for white feathers.

Detailed explanation-5: -Plumage colour is a feature used in modern poultry breeding to distinguish between breeds, strains and pure lines. It is therefore important in strain security. Sex-linked genes affecting plumage colour and patterns and rate of feather development are useful in sexing of day-old chicks.