Final answer:
The seminal vesicles contribute 70 percent of semen and secrete an alkaline fluid, while the prostate gland contributes close to 30 percent of semen and secretes an alkaline fluid high in zinc.
Step-by-step explanation:
The seminal vesicles contribute approximately 70 percent of semen and secrete an alkaline fluid that contains substances and nutrients sperm need to survive and swim in the female reproductive tract. The prostate gland contributes close to 30 percent of semen and secretes an alkaline fluid high in zinc, which is important for healthy and motile sperm. The ejaculatory ducts connect the vas deferens with the urethra and carry sperm from the vas deferens, while the secretions from the seminal vesicles and prostate gland form semen. The bulbourethral glands secrete a small amount of fluid into semen that helps lubricate the urethra and neutralize any acidic urine it may contain.