Final answer:
Men produce about 170 million sperm each day, with the process beginning at puberty and continuing throughout life, although counts may decline with age and due to factors like smoking.
Step-by-step explanation:
Men produce a remarkable quantity of sperm every day. A sexually mature male produces approximately 85 million sperm per day per testicle, which totals around 170 million sperm each day. This continuous process of sperm production, known as spermatogenesis, starts from puberty and goes on throughout a man's life. Although a single sperm cell is all that's needed to fertilize an egg, a young, healthy male may produce hundreds of millions of sperm a day.
The quantity of sperm produced can be affected by various factors, such as age, where sperm counts slowly decline after age 35. Lifestyle factors like smoking can also lower sperm counts irrespective of age. Semen volume and sperm viability are important as well, with 10-20 million live spermatozoa per milliliter considered sufficient for fertilization. A teaspoon of semen may contain hundreds of millions of sperm, indicating the extensive production by the male reproductive system.