Unlike women, men do not experience a major, rapid (over several months) change in fertility as they age (like menopause). Instead, changes occur gradually during a process that some people call andropause. Aging changes in the male reproductive system occur primarily in the testes.
If a pair of Organisms are capable of producing fertile offspring in nature they must belong to the same species
Cells make up the basic structure of an organism, and they perform basic life functions for the organism.
^the first one
