What might influence the variety of traits within a population?

Sebaceous glands are the glands responsible for the production of blackheads, an accumulation of oily material.

Arrector pili are the small muscle that is responsible for goosebumps by pulling the hair upright during fright or cold.

Eccrine glands are the perspiration glands that are plays role in temperature control by secreting water to the skin surface, which evaporates in the heat.

The hair follicle is the sheath formed of both connective and epithelial tissues.

Apocrine glands are present in the groin area and most active during puberty. These are less numerous types of the perspiration-producing gland.

Sebaceous glands or oil glands are found with hair follicles and present everywhere on the body except for the soles of feet and palms of the hands.

Hair and nails are the cells that are primarily dead keratinized cells

cutaneous receptors are the special kind of nerve endings that are sensitive to touch, pressure, or temperature.

sebaceous glands secrete oily substances that act as a lubricant for hair and skin and make them moist and smooth.

nails sports a lunula and a cuticle