The very function, or job of CELL MEMBRANES is to protect the cell from it's surroundings, or in other words, to keep it safe. It controls the movement of substances in and out of cells and organelles, like a guard watching for suspicious activity and protecting something.
The cell membrane itself is a thin, flexible layer around the cells of all living things. It separates the inside of the cells from the outside of the cells.
I believe it's the ovule.
Answer:
Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce.
= Fish
Explanation:
Its A. it prevents sperm from reaching the egg and fertilizing it.
