Atmosphere: the thin layer of air which surrounds the earth is called atmosphere,
atmos means vapour the word "atmosphere" is derived from Greek.this consists a large number of gases including oxygen,nitrogen,carbon dioxide,water vapour etc and dust particles.

biosphere: the realm of life including bacteria which live high up in the atmosphere or in deep oceans constitutes biosphere. bios means life biosphere is derived from the greek word bios.
Biosphere:- The biosphere is the global sum of all ecosystems. It can also be termed as the zone of life on Earth, a closed system (apart from solar and cosmic radiator and heat from the interior of the Earth), and largely self-regulating.

atmosphere :- 
the envelope of gases surrounding the earth or another planet is called atmosphere.