Isn't it the cell membrane? The cell membrane controls what goes in and out of the cell using active and passive transport. Osmosis being a part of passive transport.
Answer:
The correct option is A. Cooler, more dense material sink while warmer, less dense material rises.
Explanation:
Convection can simply be described as the transfer of heat energy among molecules or substances. Convection will occur if molecules of liquid or gas are given rough supply of heat. Hot liquids or gases would have the following properties:
- Their density would be less.
- They would have the ability to rise.
Whereas the cooler molecules will have the following properties:
- Their density would be more than the hot molecules.
- They would have the ability to sink.
