I believe the answer to this question is a food web.
Food Web definition: "<span>a series of organisms related by predator-prey and consumer-resource interactions; the entirety of interrelated food chains in an ecological community."
Source: </span>http://www.dictionary.com/browse/food-web
Answer:
probably the heart because you can live with just a brain stim and no brain but you would die without a heart
Yes it can absorb light if its an organelle
<span>A study of biology will help inform you about your lifestyle choices, because it will lead you to better understand the ways in which your choices about what you eat and how much you exercise actually affect the internal processes in your body and the drastic effect that you can have on them.</span>
