Question

How are bacterial and fossil species defined

Answer 1

Bacterial: a microscopic, single-celled organisms that thrive in diverse environments.

fossil Species: the fossil species must be old relative to the time of origin of the extant clade (common ancestor).

Step-by-step explanation:

Answer 2

fossil species- must be old relative to the time of origin of the extant clade.

Single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites (dependent on another organism for life). The plural of bacterium