Cell Processes and Energy worksheet focusing on osmosis, diffusion, and active transport with diagrams and vocabulary exercises.

Final Answer:
1. Osmosis
2. Diffusion
3. Active transport

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Explanation:
- In picture 1, water is moving *out* of the fish’s cells into the ocean. The fish’s cells have more water (96.5%) than the salty ocean, so water moves from high water concentration to low water concentration — that’s osmosis (a special type of diffusion for water).
- In picture 2, oxygen moves from the lungs (100 units) into the blood (40 units). It goes from high concentration to low concentration *without* energy — that’s diffusion.
- In picture 3, sodium is pumped *against* its concentration gradient: from 19 units inside the nerve cell to 155 units outside. That requires energy — that’s active transport.

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Teach the Topic:
Cells need to move things in and out — like food, waste, or water. They use three main ways:
1. Diffusion: Molecules spread out naturally from where there are *many* to where there are *few*, like perfume spreading in a room. No energy needed.
2. Osmosis: Just for water — it moves through a special door (cell membrane) from watery places to less watery places. Also no energy.
3. Active transport: When the cell must push something *the wrong way* (from few to many), it uses energy — like pumping air into a bike tire uphill.

Simple example:
You have a cup with 10 sugar cubes on one side of a screen, and 2 on the other. If you shake it gently, sugar cubes slowly spread until both sides have about 6 — that’s diffusion.
If only *water* can pass through the screen, and one side has more water, water moves to balance it — that’s osmosis.
If you use your hand to push extra sugar cubes to the side that already has more — that’s active transport (you’re using energy!).

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Practice Task:
A plant root cell has 80 units of potassium inside, and the soil has 20 units. Potassium moves *into* the cell. Is this diffusion, osmosis, or active transport? Explain why.