But fortunately for most of us, the immune system is constantly on duty to battle germs that could make us ill. The following discussion questions and activities will help your students learn about how the immune system protects them from germs and illness.
Elephants however, go through six sets of 9lb teeth during their lifetimes, with new teeth growing in to replace old ones that have worn out. An elephants starts with two front teeth that fall out after about a year and are replaced by a set of tusks.
As elephants start growing older, the longevity of their lives depends upon their teeth. From the front to the end, an elephant has 6 sets of molar teeth. The first set of adult teeth appears at the age of 20 to 25. And the last set appears at the age of 60.