Concentration gradient across the membrane. Proteins in the membrane allow specific molecules through, passively.
Answer: The carbon cycle helps regulate Earth's temperature.
Answer: The answer is Echinoderms
Explanation: The skin of most species is covered by spines, “warts,” or other projections.
The correct answer for this question is this one: "A. Has the claim been discussed on the news or other reliable media sources?"
There exists the same question from other source that has the following choices:
<span>A. Has the claim been discussed on the news or other reliable media sources?
B. Has the claim been promoted by more than one expert witness?
C. Has the claim been published in more than one periodical?
D. Has the claim been tested numerous times by more than one scientist?</span>
Answer:
So there is not an over population. Also, so that food does not run out.
