Review Article
Teena Agrawal
Abstract
About the 80 percent part of the world is covered by the water, they are with the large oceans and the seas, in them lies the photosynthetic algae, they are present about the depth of the 160 meters, it depends on the water nature and about its pollution level. Algae occur in the shores and coast, the bottom attached with any basic body (benthic algae) and some time they follow on the water by the free-living activity these are the plank tonic organism. Fresh water of the body like the ponds and the lakes and the rivers are also attached by the many kinds of the forms of the algae, and many of the species of the algae are also the terrestrial form. Algae accounts for the half of the primary production of the photosynthesis. About all the aquatic organism depends on the algae for their primary production and the water biogeochemical cycles are the result of the algae production, they are the primary producers. Algae are very valuable ecologically as well as the phylogenetically. This is the reasons in the sea one can finds the major evolutionary lineages in the oceans and in the sea. For the tracing, out the evolution of the plant world and the animals we have to understand the evolution and the phylogeny of the algae.