Osmosis and Diffusion Worksheet: Animal cells in different solutions demonstrating water movement and cell behavior.

Let's solve this Osmosis & Diffusion Worksheet step by step. We'll go through each question and then analyze the 9 beaker scenarios.

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Part A: Short Answer Questions

#### 1. Is water always able to diffuse through a cell’s selectively permeable membrane?
✔ Answer: YES (Y)
Water can pass through a selectively permeable membrane via osmosis, especially through aquaporins (water channels) in the cell membrane.

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#### 2. Are solutes always able to diffuse through a cell’s selectively permeable membrane?
✘ Answer: NO (N)
Only small, nonpolar molecules or those with specific transporters can cross the membrane. Large or charged solutes (like ions or proteins) often cannot diffuse freely unless facilitated by transport proteins.

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#### 3. The movement of molecules across a cell membrane against its concentration gradient is called...
✔ Answer: Active Transport
This requires energy (ATP) because it moves substances from low to high concentration.

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Part B: Analyze Each Beaker (1–9)

We are told:
- The solute particles cannot diffuse through the membrane.
- Only water can move (via osmosis).
- Water moves from low solute concentration → high solute concentration (i.e., from hypotonic to hypertonic side).

We need to:
- A. Draw an arrow showing direction of water movement.
- B. Label what happens to the cell (shrivel, swell, no change).
- C. Name the solution type (hypertonic, isotonic, hypotonic).
- D. Fill in missing percentages if needed.

> Remember:
> - Hypertonic: higher solute concentration outside → water leaves cell → shrivels.
> - Hypotonic: lower solute concentration outside → water enters cell → swells.
> - Isotonic: equal solute concentrations → no net movement → no change.

Also: % H₂O + % Solute = 100%

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Now let's go through each beaker:

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#### 1. Cell: 5% H₂O, 10% solute | Beaker: 20% solute

First, find % H₂O in beaker:
100% – 20% solute = 80% H₂O

So:
- Cell: 5% H₂O, 10% solute → but wait — that adds to only 15%. That must be a typo.

Wait! Let's recheck:

The cell has:
- 5% H₂O
- 10% solute → total = 15% → impossible!

But we know: % H₂O + % solute = 100%

So likely, the numbers are mislabeled.

Looking closely: It says:
- Cell: 5% H₂O, 10% solute → this is impossible unless the rest is other stuff, but in biology, for osmosis problems, we assume only water and solute.

So probably, the cell has 90% H₂O and 10% solute, and the "5% H₂O" is a typo.

Wait — actually, look at the image again:

It says:
> "Cell: 5% H₂O, 10% solute" → that can't be right.

But perhaps it's 95% H₂O, 10% solute? No, that would be 105%.

Ah! Wait — maybe it's 95% H₂O, 5% solute?

But it says: 5% H₂O, 10% solute → total 15% → not possible.

Alternatively, maybe the cell is labeled as having 95% H₂O and 5% solute, but written poorly.

Wait — looking carefully at the image:

In beaker 1:
- Cell: 5% H₂O, 10% solute → clearly wrong.

But perhaps it's a typo, and should be:

> Cell: 95% H₂O, 5% solute
> Beaker: 20% solute → so 80% H₂O

That makes sense.

So let's assume typo:
Cell: 95% H₂O, 5% solute
Beaker: 20% solute → 80% H₂O

Then:
- Solute inside: 5%
- Solute outside: 20%
→ Outside has more solute → hypertonic solution
→ Water moves out of cell → shrivel

Answer:
- A. Arrow: from cell to beaker (water leaves)
- B. Cell shrivels
- C. Solution is hypertonic
- D. % H₂O in beaker: 80%

✔ Corrected:
Cell: 95% H₂O, 5% solute
Beaker: 80% H₂O, 20% solute

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#### 2. Cell: 4% H₂O, 40% solute → total 44% → still invalid

Again, problem: 4% H₂O + 40% solute = 44% → missing 56%?

Wait — this can't be.

Possibly: Cell: 60% H₂O, 40% solute? But it says 4% H₂O.

No — maybe "4% H₂O" is a typo, and it's 60% H₂O, 40% solute?

But the beaker says: 30% solute → 70% H₂O

Wait — look at the image again:

Beaker 2:
- Cell: 4% H₂O, 40% solute → again, impossible.

Wait — perhaps it's 60% H₂O, 40% solute? That adds to 100%.

Yes — likely typo: "4% H₂O" should be "60% H₂O"

And beaker: 30% solute → 70% H₂O

So:
- Cell: 60% H₂O, 40% solute
- Beaker: 70% H₂O, 30% solute

So:
- Inside: 40% solute
- Outside: 30% solute → lower solute outside

→ So hypotonic solution → water enters cell → swell

Answer:
- A. Arrow: into cell
- B. Cell swells
- C. Solution is hypotonic
- D. % H₂O in beaker: 70%

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#### 3. Cell: 78% H₂O, 7% solute → total 85% → missing 15%

Wait — 78% H₂O + 7% solute = 85% → not valid.

But beaker: 80% H₂O, ? solute → so solute = 20%

Assume cell is 93% H₂O, 7% solute? Then 93+7=100.

But it says 78% H₂O → maybe typo?

Wait — perhaps it's 78% H₂O, 22% solute?

But it says 7% solute.

This is confusing.

Wait — maybe the cell has 78% H₂O, 22% solute? But written as 7%?

No — perhaps it's 78% H₂O, 22% solute → but written as 7%? Unlikely.

Alternative: Maybe the beaker has 80% H₂O, so 20% solute

Cell: 78% H₂O, 7% solute → total 85% → invalid.

Wait — maybe it's 93% H₂O, 7% solute → typo: "78%" should be "93%"

Yes — likely typo.

So assume:
- Cell: 93% H₂O, 7% solute
- Beaker: 80% H₂O, 20% solute

So:
- Inside: 7% solute
- Outside: 20% solute → higher solute outside → hypertonic
→ Water moves out → shrivel

Answer:
- A. Arrow: out of cell
- B. Cell shrivels
- C. Solution is hypertonic
- D. % H₂O in beaker: 80% (already given)

Wait — beaker says: 80% H₂O → so solute = 20% → correct.

So cell: 93% H₂O, 7% solute → yes.

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#### 4. Cell: 43% solute → so H₂O = 57%?
Beaker: 60% solute → H₂O = 40%

So:
- Cell: 57% H₂O, 43% solute
- Beaker: 40% H₂O, 60% solute

→ Higher solute outside → hypertonic
→ Water moves out → shrivel

Answer:
- A. Arrow: out of cell
- B. Cell shrivels
- C. Solution is hypertonic
- D. % H₂O in beaker: 40% (since 60% solute → 40% H₂O)

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#### 5. Cell: 60% H₂O, 40% solute
Beaker: 80% H₂O → so solute = 20%

So:
- Inside: 40% solute
- Outside: 20% solute → hypotonic
→ Water moves in → swell

Answer:
- A. Arrow: into cell
- B. Cell swells
- C. Solution is hypotonic
- D. % H₂O in beaker: 80% (given)

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#### 6. Cell: 18% solute → so H₂O = 82%
Beaker: 10% solute → H₂O = 90%

So:
- Inside: 18% solute
- Outside: 10% solute → hypotonic
→ Water moves in → swell

Answer:
- A. Arrow: into cell
- B. Cell swells
- C. Solution is hypotonic
- D. % H₂O in beaker: 90%

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#### 7. Cell: 18% solute → H₂O = 82%
Beaker: 80% H₂O → solute = 20%

So:
- Inside: 18% solute
- Outside: 20% solute → hypertonic
→ Water moves out → shrivel

Answer:
- A. Arrow: out of cell
- B. Cell shrivels
- C. Solution is hypertonic
- D. % H₂O in beaker: 80% (given)

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#### 8. Cell: 28% solute → H₂O = 72%
Beaker: 20% solute → H₂O = 80%

So:
- Inside: 28% solute
- Outside: 20% solute → hypotonic
→ Water moves in → swell

Answer:
- A. Arrow: into cell
- B. Cell swells
- C. Solution is hypotonic
- D. % H₂O in beaker: 80%

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#### 9. Cell: 90% H₂O → solute = 10%
Beaker: 35% solute → H₂O = 65%

So:
- Inside: 10% solute
- Outside: 35% solute → hypertonic
→ Water moves out → shrivel

Answer:
- A. Arrow: out of cell
- B. Cell shrivels
- C. Solution is hypertonic
- D. % H₂O in beaker: 65%

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✔ Final Answers Summary:

| Beaker | Cell (H₂O, Solute) | Beaker (H₂O, Solute) | Water Movement | Cell Effect | Solution Type |
|--------|---------------------|----------------------|----------------|-------------|----------------|
| 1 | 95% H₂O, 5% solute | 80% H₂O, 20% solute | Out → beaker | Shrivel | Hypertonic |
| 2 | 60% H₂O, 40% solute | 70% H₂O, 30% solute | In → cell | Swell | Hypotonic |
| 3 | 93% H₂O, 7% solute | 80% H₂O, 20% solute | Out → beaker | Shrivel | Hypertonic |
| 4 | 57% H₂O, 43% solute | 40% H₂O, 60% solute | Out → beaker | Shrivel | Hypertonic |
| 5 | 60% H₂O, 40% solute | 80% H₂O, 20% solute | In → cell | Swell | Hypotonic |
| 6 | 82% H₂O, 18% solute | 90% H₂O, 10% solute | In → cell | Swell | Hypotonic |
| 7 | 82% H₂O, 18% solute | 80% H₂O, 20% solute | Out → beaker | Shrivel | Hypertonic |
| 8 | 72% H₂O, 28% solute | 80% H₂O, 20% solute | In → cell | Swell | Hypotonic |
| 9 | 90% H₂O, 10% solute | 65% H₂O, 35% solute | Out → beaker | Shrivel | Hypertonic |

> Note: Some values were corrected due to apparent typos (e.g., 5% H₂O instead of 95%, etc.).

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🔍 Key Concept Recap:

- Osmosis: Water moves from low solute → high solute.
- Hypertonic: more solute outside → water out → shrivel.
- Hypotonic: less solute outside → water in → swell.
- Isotonic: equal → no net movement.

Let me know if you'd like a visual diagram or printable version!