Printable worksheet designed to teach and test understanding of diffusion and osmosis, featuring interactive exercises for students.

Here’s the complete solution with explanations for each question.

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## 1. Which type/s of transfer do the statements below refer to? Write YES and NO in the boxes.

| Statement | Diffusion | Osmosis |
|----------|-----------|---------|
| A substance moves from an area of low concentration to an area of high concentration. | NO | NO |
| Can happen in living cells. | YES | YES |
| A substance moves and becomes more evenly spread out. | YES | YES (water spreads out) |
| The movement does not use energy and is caused by the random movement of individual particles. | YES | YES |
| The movement requires energy from respiration. | NO | NO |
| Only water is involved in this type of movement. | NO | YES |
| Water moves from a less concentrated solution to a more concentrated solution. | NO | YES |

✔ Explanation:

- Diffusion: Movement of *any* substance (gas, liquid, solute) from high → low concentration. Passive (no energy). Happens in air, water, and cells.
- Osmosis: Specific type of diffusion — only water moves across a partially permeable membrane from low solute concentration → high solute concentration (i.e., from dilute to concentrated solution).

> ❗ Note: “A substance moves from low to high concentration” — This is active transport, NOT diffusion or osmosis. So both are NO.

> ❗ “Only water is involved…” — That’s the definition of osmosis → YES for Osmosis, NO for Diffusion.

> ❗ “Water moves from less concentrated to more concentrated solution” — This is osmosis (water moves toward higher solute concentration).

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## 2. Write TRUE or FALSE after each statement below.

a. Osmosis is the movement of water and sugars. → FALSE
→ Osmosis is ONLY the movement of water.

b. Diffusion is the movement of substance from a high concentration. → FALSE
→ It’s from high to low concentration. The statement is incomplete/incorrect.

c. Both diffusion and osmosis need lots of energy to occur. → FALSE
→ Both are passive processes — no energy required.

d. Osmosis requires a partially permeable membrane. → TRUE
→ Yes! This is essential for osmosis — it separates two solutions and allows only water through.

e. A partially permeable membrane lets all size substances through. → FALSE
→ It lets only small molecules (like water) pass — blocks larger ones (like sugar, proteins).

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## 3. Do the following statements refer to DIFFUSION or OSMSIS?

a. Shaun’s plant looked dead but when he watered it, it sprang right back up. → OSMOSIS
→ Plant cells take in water via osmosis, becoming turgid again.

b. The girl sitting two rows ahead of you put on too much perfume this morning. → DIFFUSION
→ Perfume molecules diffuse through the air from high to low concentration.

c. Yum! Something smells good. The neighbours are cooking on the grill! → DIFFUSION
→ Smell molecules (volatile chemicals) diffuse through air.

d. You put raisins in a glass of water, and they plump up. → OSMOSIS
→ Water enters the raisins (which have high solute concentration inside) via osmosis.

e. Ronald has his stinky shoes off again, and you can tell from the next room. → DIFFUSION
→ Odor molecules diffuse through the air.

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## ✔ Final Answer Summary:

Question 1 Table:

| Statement | Diffusion | Osmosis |
|----------|-----------|---------|
| A substance moves from an area of low concentration to an area of high concentration. | NO | NO |
| Can happen in living cells. | YES | YES |
| A substance moves and becomes more evenly spread out. | YES | YES |
| The movement does not use energy and is caused by the random movement of individual particles. | YES | YES |
| The movement requires energy from respiration. | NO | NO |
| Only water is involved in this type of movement. | NO | YES |
| Water moves from a less concentrated solution to a more concentrated solution. | NO | YES |

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Question 2:

a. FALSE
b. FALSE
c. FALSE
d. TRUE
e. FALSE

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Question 3:

a. OSMOSIS
b. DIFFUSION
c. DIFFUSION
d. OSMOSIS
e. DIFFUSION

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Let me know if you’d like diagrams or real-life examples to reinforce these concepts!