Organisms need to take food because you need it to survive.
Autotroph --
<span>Autotroph is </span>an organism that can form nutritional organic substances.
<span>The question "</span><span>which organisms depend on seaweeds as an energy source?" will </span>best help a student identify the role of seaweeds in the Chesapeake Bay ecosystem.
The answer is (C) they store genetic info for cellular metabolism
The 2nd and 4th answer choices sound the best to me. I personally would go for the 2nd one, explaining that the fossils of fish K and fish R and Y are similar. If you get the question wrong, I am VERY sorry. :(
In this case two kinds of selection might be applicable to this situation. For example, if the population of grey mice are more exposed to predators due some materials used in the dam then that would be an example of disruptive selection. But if the population of gray mice is less visible to predators and if the population grow, then it will be an example of Stabilizing selection. Basicaly meant, this type of situation is also known as codominancy or codominant type.