Final answer:
Sebaceous glands are located across the body, mainly associated with hair follicles, and produce an oily substance called sebum that waterproofs and lubricates the skin and hair.
Step-by-step explanation:
The location of the sebaceous glands is across most parts of the body, particularly associated with hair follicles. However, they are not found in the palms of the hands and soles of the feet. Their primary function is to produce sebum, an oily substance that helps to waterproof and lubricate the skin and hair. Sebum has the added benefit of having antibacterial properties, which inhibit the growth of microorganisms on the skin. Sebaceous glands produce more oil in response to hormonal changes, especially during puberty, becoming more active after childhood.