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.
In addition, the lower molar teeth of apes and humans have five cusps, or raised points, on their grinding surfaces. This is known as a Y-5 pattern because the area between the cusps roughly is in the shape of the letter Y. Monkeys only have four cusps on their lower molars.