Osmosis and diffusion are both examples of passive transport, neither of which requires energy to cross the cell membrane from areas of high concentration to areas of low concentration. Active transport is the process of moving molecules and ions from areas of low concentration to areas of high concentration. Active transport requires energy in the form of ATP.
Mimicry, letting off scents, camouflage, playing dead
hope this helps
Long answer short- to reproduce cells.
Ice float because it's a solid. A way to explain it to a child would be by saying it has bubbles in it so that's why it floats.
