Final answer:
The hormone that causes an increase in sebum production during adolescence is an androgen. These hormonal changes commonly lead to acne as excess sebum can clog pores and encourage bacterial growth.
Step-by-step explanation:
The hormone responsible for causing pores to open up and produce more sebum in teenagers is an androgen. Androgens are a group of hormones that play a role in male traits and reproductive activity. Present in both males and females, they are part of the changes that occur during puberty, including the stimulation of sebaceous glands to release more sebum into hair follicles. This excess production of sebum can contribute to the formation of acne in teenagers.
Acne is a common skin condition that occurs when pores become clogged by oil, dead skin, and bacteria. During adolescence, increased androgen levels cause the sebaceous glands to enlarge and produce more sebum, which can lead to clogged pores and pimples especially when coupled with other factors such as diet high in refined sugars or carbohydrates.