The Cỉculatory system is an organ system that permits blood to everywhere in the body and transport nutrients, oxygen, carbon dioxide, ...to help fighting diseases ,.... The main parts of the Circulatory system are heart , lungs , veins , vessels, arteries,...
Well, on average 2/3 of a persons weight is water.
Answer: False
Explanation:
Protozoans are not the organism that fix nitrogen for the plants. The organism that fix nitrogen to convert it into a form which can be used by plants are known as diazotrophs.
These are bacteria and archae that fix nitrogen gas found in the atmosphere into more usable form such as ammonia.
These organism can grow without any external source of fixed nitrogen. Example: Rhizobia and azospirillium.
