Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..
The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..
Some of the body movements can be controlled at will, others cannot. The body has a motor program, which is the pattern ..
This tutorial introduces flowing water communities, which bring new and dithering factors into the equation for possible..
Humans are capable of only one mode of reproduction, i.e. sexual reproduction. Haploid sex cells (gametes) are produced ..
According to Charles Darwin's theory of natural selection, preferable genes are favored by nature in the gene pool, and ..