Frank S. Cook, age 17, of Junction City, Oregon, for his question:

What causes a deer to be an albino?

An animal's coloring is determined by a unique package of genes, inherited from both sides of the family. In humans, the color of skin, hair and eyes is determined by genes that govern the production of dark brown pigment called menalin. Similar biochemical pigments govern the family color schemes of all plant and animal species. But in rare cases, the system fails. An individual plant, animal or person inherits a genetic pattern that is unable to produce the usual surface coloring material. This causes albinism.

The parents of a pink eyed, snow white deer may have normal coloring. But the genes of their albino offspring could not create the family pigments. His colorless hair appears white. His eyes are pink because there is no pigment to conceal their tiny blood vessels. A few albino individuals occur now and then in all animal species. Partial albinos are more common. Their production of pigments is limited and their family coloring is paler than normal.