Final answer:
A mature male produces about 85 million sperm per testicle per day, totaling approximately 170 million daily. Over a lifetime, this can exceed a quadrillion sperm cells. Only one sperm is needed to fertilize an egg, but sperm production lessens with age and factors like smoking can reduce sperm counts.
Step-by-step explanation:
A sexually mature male can produce an astounding number of sperm, typically hundreds of millions each day. To break it down, approximately 85 million sperm per day are produced per testicle, resulting in a combined total of about 170 million sperm every day.
Consequently, over a man's lifetime, more than a quadrillion (1,000,000,000,000) sperm cells may be produced. However, to fertilize an egg, it only takes one single sperm. Sperm production begins at puberty and usually continues uninterrupted until death.
Over time, certain factors such as smoking can further affect sperm counts, negatively impacting the total number produced. Considering sperm production cycles, each cycle takes approximately 64 days to go from spermatogonia to fully formed sperm, with a new cycle commencing about every 16 days.
When discussing conception, despite the chance for hundreds of millions of sperm to be released during sexual intercourse, the journey for sperm is not trivial. A sperm cell may have to swim roughly 8 inches in an hour, ultimately swimming about 192,000 times its own length to reach an egg.
In assisted reproductive techniques, such as intracytoplasmic sperm injection (ICSI), a single sperm is injected directly into an egg, especially in severe cases where sperm count is exceptionally low or nonviable for natural fertilization.