Conservation of Energy:
As a projectile is launched into the air KE is at its maximum. As the projectile gains altitude PE becomes greater than KE. At the top of its arc, PE is at its maximum. The whole cycle reverses itself on the way down.
Natural selection can cause speciation, which increases the biodiversity of an ecosystem. Several bacterial colonies are placed on a petri dish that contains agar with antibiotics. After 24 hours, ninety percent of the original bacteria die, but the remaining ten percent survive and later reproduce.
A hypersensitive reaction to a specific antigen in the environment is a(n) _ALLERGY_.