Answer:
C.
Explanation:
Food chains focus on one set of organisms and their predators/prey, while food webs show multiple for each. Hope this helps. :)
Take for example - you touching something sharp and instantly moving your hand away.
Sensory neurons in your fingers detect the external stimuli of the sharp object and send a nerve impulse to the spinal cord (does not reach brain) and is sent back to a motor neurone - attached to an effector that moves the muscle and moves the hand away. This is a rapid reflex action and involuntary.
Answer:
The decrease of a certain good source.
Answer:
All the above
Explanation:
If I understand the way the question is posed, the answer would be all of the above.