What is "biospheres"

Usage examples of "biospheres".

Inside each herd-ship, hundreds of biospheres were painstakingly repro duced down to the microscopic flora and fauna of the topsoils.

The Ithorians harvested plants from the biospheres of the ships, but particularly on their huge groundships, they also harvested from the abundant forests of Ithor-taking nourishment from fruits and grains, creating medicines from saps and pollens, using plant fibers to create fabrics and ultrastrong porcelains, harvesting minerals and energy from otherwise unusable roots and stems.

The planet itself seems to be divided into many more than a thousand separate and distinct biospheres, each with its own dominant life form and supporting its own flora, fauna, atmospheric conditions, and the like.

Do we owe our existence to a mighty stellar catastrophe that elsewhere destroyed biospheres and worlds?