Answer:
<h2>D. Competitively dominant to other organisms in the ecosystem</h2>
A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
<em>Hope that helps! :)</em>
<em></em>
<em>-Aphrodite</em>
Explanation:
Answer:
cellular membranes
Explanation:
Cellular membranes are selectively permeable because they allow only certain molecules to cross into and out of the cell. The phospholipid bilayer is a selectively permeable membrane that surrounds all biological cells. The movement of molecules across the cell membrane bilayer can occur by passive transport (does not require energy) or active transport (requires energy). For example, water molecules pass passively through the cell membrane (passive transport), while other molecules pass through transmembrane proteins against a concentration gradient (active transport).
The last three are correct
