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 ânormalâ adult human has 32 teeth. An adult should have 32 teeth with 8 incisors, 4 canines, 8 premolars, and 12 molars which include the four wisdom teeth. Humans develope 2 sets of teeth in their lives. the first set known as baby teeth began to come though at about age 6 months. They eventually have about 20 teeth as children before they began to lose them. The second, permanent set of teeth consists of 32 teeth. Twenty-eight of them appear between the ages of about 6 and 12 years. Secondary teeth do not push deciduous teeth out of their sockets; instead, a group of cells (odontoclasts) forms in front of tip of second tooth and dissolves the base of first tooth.