Gradual thinning and graying of the hair occurs naturally with age. Thinning is caused by , whereas graying is caused by .
a. destruction of the germ centers that produce hair follicles; cessation of pigment production
b. cessation of pigment production; destruction of the germ centers that produce hair follicles
c. decrease in epidermal cells; changes in collagen content
d. changes in collagen content; decrease in epidermal cells
Question 2
Most facial wrinkling experienced by adults is
a. inevitable. b. genetic.
c. caused by an overuse of vitamin E.
d. preventable if one limits exposure to the sun's ultraviolet rays and doesn't smoke.
A melanistic jaguar is a colour morph which occurs at about 6% frequency in populations.
Structure of a hair and its associated sebaceous gland.
Cross-section of skin and a hair follicle. Note the shaft of the hair, the root, and papilla
Comic strip on hair
The transition between steps usually occurs at a temperature that would not interfere with cold ...
Cystic fibrosis is caused by a mutation in a protein called CFTR