Skin Color and Hair

Skin color is due primarily to the presence of a pigment called

• Melanin

• Eumelanin

• Pheomelanin

People with light complexioned skin mostly produce

• Melanin

• Eumelanin

• Pheomelanin

Pheomelanin is

• Dark brown to black

• Red to yellow

• An absence of color

• A type of melanin

Where is melanin produced?

• Epidermis

• Dermis

• Hypodermis

• Subcutaneous layer

Nature has selected for people with _________ in tropical latitudes where UV rays are the most intense

• Darker

• Lighter

Tanning is primarily

• An increase in the number and size of melanin granules

• Stimulation of UV rays

• Acclimatization to the seasonal change

• All of the above

UVB rays are needed to help

• Decrease melanin production

• Produce calcium

• Produce Vitamin D

• Increase pheomelanin

Too much UV rays penetrating the skin can cause

• Anemia

• An uptake of calcium

• Increase in fat production

• Darkening of the skin

Which of the following behaviors has lead to Vitamin D deficiencies such as rickets disease in the US?

• Popularity of soda

• Minimal time outdoors

• Alternatives to milk

• All of the above

True or False. In some species the survival value of having a camouflaged body can be more important than the selective pressures of UV radiation

• True

• False