Why have biologists found it so difficult to develop a precise definition for life? Please help

Which experiment would most likely contain experimental bias ?

Most of the fossils found in virginia are in the coastal plain, valley, ridge, and appalachian plateau regions, best suggesting that these geographic provinces a) were once covered by seawater. b) are the oldest parts of virginia. c) have a great deal of karst topography. d) have large amounts of sedimentary rock.

What would most likely happen to a unicellular organism if it was exposed to a hypotonic solution for an extended period of time?