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.
The tusks of Asian elephants are smaller than those of African elephants. Both African and Asian elephants have 26 teeth, including their two tusks, which are their upper incisors. Elephants have 12 molars; each is the size of a brick and weighs 4 to 4.5 pounds. New teeth develop at the back of the elephant's mouth. They move horizontally in the mouth until they become worn out as they approach the front. An elephant's teeth are replaced six times during its lifetime. Learn more about Elephants