The Biosphere is made up of all living organisms on earth. The Biosphere includes between 3 and 30 million species of plants, animals, and fungi, and also two kinds of single celled living things: those without nuclei("prokaryotes") such as bacteria, and those with nuclei("eukaryotes) such as protozoans. The Biosphere extends over the earth in a thin layer that is only a few kilometres (a few kilometres from the earths surface at that spot). J.B

The definition of Biosphere is: J.B
the bio refers to biology and everything biological. The sphere refers to a "bubble" around earth in which the biological things live. J.B