Osmosis & Diffusion Quiz

Why are cells small?

It affects how materials move in and out of a cell. Things move across the cytoplasm and if it were bigger, it would take longer for materials to reach the center of the cell. It would also take longer to get wastes that could be poisonous to be removed. If it grew too large, it could not function efficiently to survive.

What is the difference between osmosis and diffusion?

Osmosis is the movement of water molecules through the cell. Diffusion is the movement of molecules, such as oxygen, in and out of a cell.

selectively permeable

The cell's membrane is like a gatekeeper or like a castle. It allows some things to enter, as well as it allows some things to exit.

Using diffusion, explain what occurred to the drop of food coloring in the container of water.

The molecules (from the drop of food coloring) moved from a more concentrated area to a less concentrated area spreading evenly throughout the volume of water.

passive transport

The movement of dissolved materials across the cell membrane without needing the cell's energy.

active transport

The movement of materials through the cell membrane need to use the cell's supply of own energy.

diffusion

The movement of small molecules from a higher concentration to an area of lower concentration.

osmosis

The process by which water molecules are able to diffuse through the cell membrane.