Question

What do you mean by melanin? List 2 abnormalities of melanin pigmentation.

Answer 1

The color of the skin is primarily influenced by the amount of a pigment called melanin.
It is present in the cells of the malpighian layer.
Different quantities of melanin are present in different human races. (1marks)
It acts as an umbrella to protect the inner parts of the body from the harmful effects of the ultraviolet rays of sunlight.
It can absorb and reduce the impact of UV rays.
Those people with a fair skin tone, on continued exposure to sunlight develop tan, but the original color tone of their skin can be restored with time.(1marks)

Albinism and leucoderma are two notable abnormalities of skin pigmentation.
Albinism is a disorder in which the body cannot produce melanin.
Due to this, the skin becomes pale and hair is white.
Leukoderma is a skin disease that causes loss of skin pigmentation (melanin) that leads to skin whitening.
The white patches on the skin are termed as leukoderma.(1marks)