Question

All of the following are true of the pigment melanin except that it

a) is produced by cells called melanocytes.
b) decreases in concentration within cells during exposure to the sun.
c) is usually some shade of brown or black.
d) protects DNA from the damaging effects of UV radiation.
e) is released through melanosomes.

Answer 1

The incorrect statement about melanin is that its concentration decreases in cells during exposure to the sun; in fact, melanin concentration increases to protect the skin from UV radiation.

Step-by-step explanation:

All options except option (b) are true of the pigment melanin. Melanin is a brown or black pigment produced by melanocytes, which protects our DNA from UV damage. When exposed to the sun, melanin production increases, hence its concentration within the cells does not decrease. Melanocytes produce melanin and store it in organelles called melanosomes.

When these melanosomes are filled with melanin, they are transferred to the keratinocytes, which are the predominant cells in the outermost layer of the skin. The increase in melanin results in a darker skin tone, known as a tan, and this higher concentration of melanin serves as a natural protector against the harmful effects of the sun's rays.

Therefore, the statement that is not true about melanin is (b) “decreases in concentration within cells during exposure to the sun,” as it actually increases to provide protection against UV radiation.