Most humans (and vertebrates, in general) are genetically "programmed" to produce a brown skin pigment known as melanin. Albinis
m--the inability to produce melanin—is inherited in humans as an autosomal recessive trait. An individual with genotype AA or Aa will have normally pigmented skin, whereas an individual with genotype aa will produce no melanin. The albino's skin is very pale white, and the (highly vascularized) irises of the eyes appear red because no melanin obscures the red reflectance of blood.
Most humans (and vertebrates, in general) are genetically "programmed" to produce a brown skin pigment known as melanin. Albinism--the inability to produce melanin—is inherited in humans as an autosomal recessive trait. An individual with genotype AA or Aa will have normally pigmented skin, whereas an individual with genotype aa will produce no melanin. The albino's skin is very pale white, and the (highly vascularized) irises of the eyes appear red because no melanin obscures the red reflectance of blood.
The frequencies aa (Parental genotype male) and Aa (Parental genotype female, predict the frequencies of all genotypes and phenotypes expected to result from the cross of an albino male with a heterozygous female.
