Answer:
A control group is a set standard so that comparisons can be made to see what your experiment did. The experimental group is the group that has been changed. A control group also allows you to determine your variables.
Explanation:
Receptors on the plasma membrane either recognize a particle as acceptable or foreign.
<em>An answer choice that is not an example of an organism responding to a stimulus would be;</em>
B) squinting your eyes when walking into bright sunlight
<u>Squinting your eyes in bright sunlight is an involuntary action, and does not require any kind of stimulus. </u>
Can be extremely corrosive
