Question

What's the condition that animal cells require

Answer 1

The answer is Isotonic.
If I remember correctly, animal cells do not have cell walls, meaning when the animal cells are put into a hypertonic solution, their cells will shrink, which will eventually lead animal cells to a dehydrated stage.
When animal cells are put into a hypotonic solution, the cells will actually burst because of the water flow. However, plant cells require hypotonic solution because as you may know, they have cell walls, which indicates when their cells start to swell up, the cell wall within the plant cells will prevent from swelling.