One function of the male reproductive system in
mammals is to
(1) produce insulin necessary for sexual
reproduction
(2) transport eggs necessary for fertilization
(3) allow for delivery of gametes needed for
reproduction
(4) provide protection for the developing zygote

The best answer is (3)

The male reproductive system is designed to make sperm or male gametes and is adapted to provide for the delivery of these gametes to the female to allow for fertilization. It consists of:

1. Testes- produces sperm and the hormone testosterone

2. Scrotum- pouch enclosing the testes keeping the sperm at an optimum temperature.

3. Vas deferens- tube that carries sperm away from the testes.

4. Prostate gland- adds lubricating and other fluids to the sperm.

5. Urethra- tube through the penis carrying sperm to the outside of the body.

6. Penis- adaptation for internal fertilization of the female.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.