This video shows some excellent microscopic views of human sperm and the tubules within the testes where the sperm form. When we consider that the adult human male produces some 100 million new sperm every day, and that it requires about 10 weeks to develop each one, the sperm-producing mechanism seems like one of the marvels of nature.

The film’s narrator calls sperm a highly efficient machine for delivering a gene packet, and that is exactly the purpose of these microscopic cells during reproduction. There is growing concern that sperm counts in human males are decreasing in some areas of the world, and it is not entirely understood why this may be happening.

Please watch the following video clip and answer the corresponding follow-up questions.

The Testes

1			In terms of human reproduction, why is it necessary to have such huge numbers of sperm in order to fertilize a single ovum?
2			Why is it that some men have had difficulty with their fertility because of wearing insulated underwear?