Answer:
C. A concentration gradient must exist.
Hi There! :)
<span>What is a fish bigger than a salmon but smaller than a dolphin
</span><span>Porpoises</span>
A heterotroph is an organism that relies on complex organic substances for nutrition. <span>A </span>heterotroph<span> is an animal that can't make its own food supply, so they have to eat other things, like plants or other animals, to survive. Hope this answers the question.</span>
Answer:
<em>Carbon </em><em>dioxide</em><em> </em><em>is </em><em>necessary</em><em> </em><em>for </em><em>photosynthesis</em><em> </em><em>because </em><em>plants </em><em>make </em><em>their</em><em> </em><em>food </em><em>only </em><em>in </em><em>the </em><em>presence</em><em> </em><em>of </em><em>carbon </em><em>dioxide</em><em> </em>
I hope this will help you :)
