Question

question 20
the testes produce
testosterone
estrogen
cortisol
thyroid hormone (th)

question 21
when is glucagon secreted?
when blood glucose levels are high
when blood pressure is low
when blood glucose levels are decreasing
when fatty acids are released into the blood

Explanation:

For Question 20, the testes are the male gonads and their main hormonal product is testosterone. Estrogen is mainly produced by the ovaries in females, cortisol by the adrenal glands, and thyroid hormone by the thyroid gland.
For Question 21, glucagon is a hormone that raises blood - glucose levels. It is secreted when blood glucose levels are decreasing to stimulate the liver to break down glycogen into glucose and release it into the blood.

Answer:

Question 20: Testosterone
Question 21: When blood glucose levels are decreasing