Hair pigmentation in mammals follows the generic enzymatic pathway depicted below. Enzyme A synthesizes a black pigment from a p
recursor, and the contribution of enzyme B results in the final agouti pigment: Precursor molecule (colorless) Black pigment Agouti pigment
Each enzyme is coded by a single allele with complete dominance. If a crossing design begins with true breeding parents for coat color with the genotypes AAbb and aaBB. What will be the expected F2 genotypic and phenotypic ratios of the eventual F2 progeny?
(See figure below, where meiosis I begins with a diploid (2n = 4) cell and ends with two haploid (n = 2) cells.) In humans (2n = 46), who have 23 pairs of chromosomes, the number of chromosomes is reduced by half at the end of meiosis I (n = 23).
The correct answer among the choices listed above is option C. It is important that a plant's phloem extends into its leaves because the phloem <span>collects the sugars made during photosynthesis and carries them around the plant. Hope this answers the question.</span>
