The food chain ?
Sun
Primary producers
Primary consumers
Secondary consumers
Tertiary consumers
Answer:
three types of stimuli—mechanical, thermal, and chemical; some endings respond primarily to one type of stimulation, whereas other endings can detect all types. Chemical substances produced by the body that excite pain receptors include bradykinin, serotonin, and histamine."
Explanation:
From edge
A mutation is one form of genetic variation.
