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.
A fully developed horse of around five years of age will have between 36 and 44 teeth. All equines are heterodontous, which means that they have different shaped teeth for different purposes. All horses have twelve incisors at the front of the mouth, used primarily for cutting food, most often grass, whilst grazing. horse can have between zero and four canine teeth, also known as tusks (tushes for the deciduous precursor), with a clear prevalence towards male horses (stallions and geldings) who normally have a full set of four. Fewer than 28% of female horses (mares) have any canine teeth.