Which of the following methods involves counting the number of organisms in a specific area?
a.
mark/recapture
b.
direct observation
c.
sampling
d.
indirect observation

The chemical form of energy that is useable by the cell to do work

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.

Ascientific idea becomes valid when it is what?