How do sebaceous glands protect the skin normally

If this oil mixes with dead skin cells and blocks a pore, it can produce a pimple. Sebaceous glands produce oil called sebum that moves up hair follicles to the surface of the skin, where the oil lubricates skin and hair. The gland may keep producing oil when the opening is blocked, leading to a pimple.

Mutagen is an environmental agent that changes the DNA.