Gradual, age-related loss of elasticity of the lens of the eye is:

Gradual, age-related loss of elasticity of the lens of the eye is:
 a. a cataract.
  b. glaucoma.
  c. presbyopia.
  d. presbycusis.

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A clouding of the lens of the eye is:
 a. a cataract.
  b. glaucoma.
  c. presbyopia.
  d. presbycusis.

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Which statement best describes keratinocytes?
 a. A protein found in connective tissue that promotes resiliency of the skin.
  b. A pigment that gives color to skin and hair.
  c. A fibrous protein that is the main support of bone, ligaments, cartilage, and tendons.
  d. Cells that make up the outer layer of the skin.

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Which statement best describes collagen?
 a. A protein found in connective tissue that promotes resiliency of the skin.
  b. A pigment that gives color to the skin and hair.
  c. A fibrous protein that is the main support of bone, ligaments, cartilage, and tendons.
  d. Cells that make up the outer layer of the skin.

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Hair begins to gray as the production of __________ decreases.
 a. elastin
  b. melanin
  c. collagen
  d. keratinocytes