Which is unpaired gland in male reproductive system of human?

In humans, the male reproductive system consists of the following organs:
2 testes in the scrotum, 2 epididymides, 2 deferent ducts (vas deferens), 2 spermatic cords, 2 seminal vesicles, 2 ejaculatory ducts, 1 prostate gland, 1 penis. The prostate gland is the unpaired gland that lies in the pelvic cavity in front of the rectum, secretes a thin, milky fluid, that makes up about 30% of semen, and gives it its milky appearance. It is slightly alkaline, which provides a protective local environment for sperm arriving in the acidic vagina.