Texas FFA Livestock Judging Practice Test

The hormone primarily responsible for the development of masculine traits in animals is testosterone. This hormone plays a crucial role in the growth and development of male reproductive tissues, including the testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle mass, bone density, and body hair.

In males, testosterone is essential for the development of behaviors typically associated with masculinity, including aggression and competitive behaviors that can impact social hierarchy and reproduction. The secretion of testosterone is heavily influenced by the pituitary gland, which releases luteinizing hormone that stimulates its production in the testes.

Other hormones listed do not primarily influence masculine traits. Estrogen is typically associated with female characteristics and reproductive functions. Progesterone is involved in the menstrual cycle and pregnancy, primarily in females. Insulin regulates glucose metabolism and is critical for energy management but does not play a direct role in the development of sexual characteristics. Thus, testosterone stands out as the key hormone for masculine trait development.