One reason that bacteria can be harmful is that they: a. can remove nitrogen gas from the air. b. have cell walls with peptidoglycan. c. can produce toxins that kill other cells. d. live in the digestive tracts of animals.

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies