Year 7 Science · Unit 1 · Lesson 07
Apply Worksheet
Learning Goals
Order the steps
Number the events from 1 to 6 to show the correct order for observing plant cells under a light microscope. Event 1 = what happens first.
| Order | Step |
|---|---|
| Switch to high power magnification and identify the nucleus and cell wall. | |
| Add a drop of iodine stain to the onion skin to make cell parts easier to see. | |
| Observe the slide under low power (×40) to find a clear area of cells. | |
| Carefully lower a coverslip on top of the onion skin, avoiding air bubbles. | |
| Peel a thin, transparent layer of onion skin and place it flat on the glass slide. | |
| Add a drop of water to the slide to keep the onion skin moist. |
Compare two
Complete the table to compare a plant cell and an animal cell. Fill in as many cells as you can — use "present", "absent", "large", "small", or a brief description.
| Feature | Plant Cell | Animal Cell |
|---|---|---|
| Cell wall | ||
| Chloroplasts | ||
| Vacuole size | ||
| Typical shape | ||
| Examples from everyday life |
1. When scientists observed onion skin cells under a microscope, they could NOT see any chloroplasts. Using your knowledge of plant cell structure, explain why onion skin cells do not contain chloroplasts.
2. A student says: "Plant cells don't need mitochondria because they have chloroplasts to make energy." Do you agree or disagree? Use evidence from the lesson to support your answer.
Wrap Up
In one sentence, what was the main idea of this lesson?