Grade 8 · Integrated Science · Living Things and Their Environment
The Cell: Grade 8 Integrated Science
Here is what the KICD curriculum design asks for in The Cell, with a sample lesson plan, notes and an exit check you can read before you teach. In Fuma, the same lesson comes out of your own scheme of work, starting from the lesson your class has reached and dated to your term.
Aligned to the KICD curriculum designSample — review before you teach
What learners should be able to do
Specific learning outcomes, word for word from the KICD curriculum design.
a)describe the structure of plant and animal cells as observed under a light microscope
b)describe the functions of components of cells seen under the light microscope
c)compare plant and animal cells as observed under a light microscope
d)determine the magnification of cells under the light microscope
e)appreciate the role of cells in living things
Key inquiry questions
What makes up plant and animal cells?
A sample lesson plan: Introduction to the Cell: Observing Plant Cells
This is a sample. Read it and change it for your class before you teach it. In Fuma, everything stays a draft until you approve it.
Grade 8 · Integrated Science · 40 minutes
describe the structure of onion epidermal cells as observed under a light microscope
prepare a temporary mount of onion epidermal cells and observe it under a light microscope
appreciate the role of cells as the basic units of living things
A sample lesson plan
Time
Teacher
Learners
Introduction5 min
Teacher:
Display a whole onion bulb and a piece of onion epidermis.
Ask learners what makes up the onion and all living things.
State the lesson topic and outcomes on the board.
Learners:
Respond to questions about what living things are made of.
Recall previous knowledge of cells as basic units of life.
Listen as the teacher states the topic.
Preparing and Observing Onion Epidermal Cells15 min
Teacher:
Demonstrate peeling a thin layer of onion epidermis using forceps.
Show how to place it on a slide, add a drop of iodine and gently lower a coverslip.
Guide learners to focus under low power using the coarse adjustment knob.
Circulate and help groups focus on their own mounts.
Learners:
Watch demonstration of peeling and mounting onion epidermis.
In groups, peel a thin piece of onion epidermis and mount it with iodine.
Place slide on microscope stage and focus under low power.
Observe the cells and describe what they see to group members.
Drawing and Labeling Onion Cells10 min
Teacher:
Ask each learner to draw what they observed under low power.
Instruct them to label three visible structures: cell wall, nucleus, cytoplasm.
Display a chart of a plant cell for comparison.
Learners:
Draw two or three onion cells from the microscope field of view.
Label the cell wall, nucleus, and cytoplasm on their drawing.
Compare their drawing with the plant cell chart.
Discussing Cell Structures and Functions5 min
Teacher:
Ask learners to state the function of each labeled part.
Summarize that cells are the basic units of life.
Relate findings from onion cells to the key inquiry question.
Learners:
Describe function of cell wall, nucleus, and cytoplasm from observation.
State that all living things are made of cells.
Answer the key inquiry question in one sentence.
Shown: the first 35 minutes of the 40-minute lesson.
Sample teaching notes
Teaching notes are for you at the board: the subject knowledge and what to watch for.
Content Mastery for the Teacher
Why we use the onion. The onion (Allium cepa) bulb is a store of food, not a green leaf. The scale leaves you peel are underground, so they never receive light and never photosynthesise — that is why they are white/pale and why the cells contain no chloroplasts. This is why the onion is a good specimen: the cells are large, see-through, and their internal structures are not hidden behind green pigment. Do not let learners think onion cells are "simple" cells — they are ordinary plant cells that simply lack one organelle.
Why iodine. Iodine solution (iodine in potassium iodide, a weak brown solution) has two jobs:
1. It stains the nucleus and cytoplasm yellow-brown, making the nucleus stand out. Without stain, the nucleus is almost invisible — pale grey against pale grey.
2. It increases contrast, so the cell walls and cytoplasm become easier to see.
Iodine is not a fixative or a cleaning agent. If a learner says "iodine makes the cells bigger", correct that immediately — the cells are already that size.
What you will actually see under low power (×10 objective, ×10 eyepiece = ×100).
- Brick-shaped cells packed in a single layer, fitting together like tiles on a wall or bricks in a wall.
- Cell wall — a clear, thick double line at the edge of each cell. It is non-living, made of cellulose, and it gives the cell its fixed shape.
- Nucleus — one dark, round or oval dot inside each cell, usually pushed to one side.
- Cytoplasm — the pale granular material filling the rest of the cell between the wall and the nucleus.
- Vacuole — a large clear space in the centre of the cell; it may be visible, but it is not one of the three structures learners are required to label in this lesson.
Misconceptions to Watch For and Correct
Misconception 1: "Onion cells should have green chloroplasts."
Why it forms: Most diagrams of a plant cell learners have met shows a green cell with chloroplasts. They have also been told "plants make food using sunlight", so they expect every plant cell to be green.
How to surface it: After two or three minutes of focusing, walk round and ask each group: "Do you see any green dots?" When a group says no, say: "Good. If you did see green, you would be looking at the wrong part." If a group says yes, ask them to describe what they see — it is almost always the yellowish-brown stain of iodine or the dark edge of the cell wall, not chloroplasts.
A quick exit check, with answers
1.A learner peels a thin layer from a red onion scale leaf and observes it under a light microscope. Which structure will the learner NOT see in these cells?
A. Chloroplast
B. Cell wall
C. Nucleus
D. Vacuole
Show answer
A. Chloroplast
2.True or false: Onion epidermal cells and animal cells both contain a nucleus and cytoplasm.
Show answer
True
3.State two structures you would draw and label in an onion epidermal cell as seen under a light microscope.
Show answer
Any two of: cell wall, cell membrane, nucleus, cytoplasm, vacuole.
4.A learner is given an onion, a slide and a light microscope. (a) Name the instrument used to peel off a thin layer of the onion. (1 mark) (b) State why the layer must be very thin. (2 marks) (c) Give one reason why a coverslip is placed on the specimen. (2 marks)
Show answer
(a) Forceps (accept a scalpel or razor blade used to lift the edge). (b) So that light can pass through it, making the cells clear and easy to see. (c) To protect the specimen and to hold it flat so it does not dry or shift.
Outcomes and inquiry questions are quoted from the KICD curriculum design. The lesson plan, notes and exit check are Fuma's draft. Fuma is built from the KICD designs; KICD has not endorsed it.