A cell membrane has consists of phospholipids. They are lipids with a phosphate group such as (PO3/4). They are hydrophilic meaning that they allow water to pass through proteins well some at least- but it might be needed to move molecules throughnthe membrane as well. But basically it's just a composed bilayer of phospholipids with hydrophobic acid tails so that they could all meet with one another. The form complexes into function to describe or to identify the cells to anothers cells.
Hope this helps.
I'm at a loss between A & C but I'm not sure, I'd go with A
Answer:
C
Explanation:
To send signals to the blood vessels to constrict or dilate , to increase or decrease blood flow respectively.
If a species is said to be extinct, then that species is reduced to zero. There are none living in existence. The affects to other organisms of its extinction would depend on their value to the ecosystem. Regardless, extinction completely stops evolution of the species extinct.
