Explain what happens to animal cells if they are put in fresh water

They will actually explode or burst

So What happens is the pure water outside has a high water potential while the cytoplasm inside the animal cell is a low water potential, water will diffuse down a water potential gradient through the semi-permeable membrane of the animal cell and cause the cell to swell (inflate like a fully-blown balloon), the result is that the delicate, elastic cell membrane can't tolerate the internal pressure coming from the cytoplasm so it tears causing the cell to burst.

Size and shape of continents