The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..
Multicellular organisms evolved. The first ones were likely in the form of sponges. Multicellularity led to the evolutio..
A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..
Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..
This tutorial looks at the relationship between organisms. It also explores how energy is passed on in the food chain an..
This tutorial describes the different types and causes of brain damage. Find out how genetics, physical injury, lack of ..