What is the medical term for baldness of the scalp?

Alopecia is the medical term used to describe hair loss, particularly baldness of the scalp. It encompasses various types of hair loss, including alopecia areata, which is characterized by patchy hair loss, and androgenetic alopecia, which specifically refers to hereditary baldness that is influenced by genetic factors and hormonal changes. The term "alopecia" itself can refer broadly to any form of hair loss, making it the correct answer for identifying baldness on the scalp.

The other terms listed relate to hair and hair growth but do not specifically denote baldness. For instance, "androgenetic" refers to a specific pattern of hair loss influenced by androgens but does not, on its own, encompass the concept of baldness in a general sense. "Hypotrichosis" refers to a condition of having less hair than normal, while "hypertrichosis" denotes excessive hair growth. Thus, while these terms may be associated with hair characteristics, they do not directly define baldness in the way that alopecia does.