Final answer:
Sebaceous glands secrete sebum for lubrication and waterproofing hair but do not contain the blood and nerve supply for hair growth; this is provided by capillaries in the dermis.
Step-by-step explanation:
False. While the sebaceous glands are associated with hair follicles and provide sebum which lubricates and waterproofs the hair, they do not contain the blood and nerve supply necessary for hair growth. The nutrients needed for hair to grow are supplied by a bed of capillaries associated with each hair follicle, and hair growth is also aided by the follicle's stem cells. The capillaries are embedded in the dermis layer of the skin, along with a nerve ending and a tiny muscle called arrector pili, which together contribute to the hair growth process.