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- 1Recall the meaning of specialised cells and identify examples from plant and animal tissues.
- 2Display a chart showing a maize plant leaf and a human finger side by side. Ask learners: What do you notice about the structure of the leaf surface and the skin on the finger? Are all cells the same size and shape? Learners discuss in pairs for 1 minute, then share observations with the class to activate their prior knowledge of cell diversity.
- 3Show a Science kit specimen of an onion epidermis under magnification on the chart. Ask: Why might some cells in a plant look different from others? Learners write their ideas in their exercise books, then a volunteer shares their answer to bridge to the concept that different cells have different jobs.
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- UNDERSTANDING SPECIALISED CELLS AND THEIR FORMATION
- 1Use the Textbook to define specialised cells: cells that have changed shape and structure to perform a specific job. Write this definition on the board and explain that when a basic cell divides and grows in a special environment, it becomes specialised. Give the example: Ama's father is a farmer who grows cassava — just as cassava roots specialise to store food, some plant cells specialise to transport water.
- 2Guide learners to brainstorm in groups of four how a cell might change to suit its job. Each group considers one scenario: a cell that needs to move quickly, a cell that needs to store food, or a cell that needs to transport water. Groups record their ideas on paper, then a representative from each group shares with the class. Confirm that specialised cells form through a process called differentiation, where cells receive chemical signals during development that tell them which job to do.
- 3Ask learners to explain in their exercise books: How would a guard cell in a leaf be different from a root storage cell, and why? This helps them connect form to function as they understand specialisation.
- 4Struggling learners: provide a partially completed comparison table with two specialised cells already labelled; they add one more difference or similarity with teacher support.
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- 1Textbook
- 2Science kit/specimens
- 3Chart/diagram showing onion epidermis and human tissue
- 4Exercise book
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- 1Ask the class: Can a cell change its job once it becomes specialised? Take responses and clarify that most specialised cells keep their job for life. Learners discuss in pairs whether specialisation is helpful or limiting for an organism, then share conclusions with the whole class.
- 2Invite learners to stand and mime the action of a specialised cell doing its job — for example, a guard cell opening and closing, or a nerve cell carrying a message. Other learners guess which cell is being acted out. This physical consolidation helps embed the concept of cell specialisation.
Exercise
- 1In your exercise book, write two sentences explaining what a specialised cell is and give one example from either a plant or a human body. Draw a simple diagram of your chosen specialised cell and label one feature that helps it do its job.
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- 1Identify the names and shapes of specialised plant cells by observing them on charts and video.
- 2Show a chart displaying epidermal cells, guard cells, cambium, and xylem cells from a dicotyledonous plant such as a bean plant. Ask learners: Which of these cells do you think moves water up the stem? Which cells control how much water leaves the leaf? Learners point to the cells and discuss their predictions in pairs to activate prior knowledge of plant cell functions.
- 3Display a short video clip (or use a detailed chart) showing the cross-section of a maize leaf. Ask: Can you name the shape of each cell type — are they square, round, or brick-shaped? Learners sketch and label the cells they see in their exercise books, naming them as they identify shapes, to prepare them for examining specialised cells more closely.
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- OBSERVING AND NAMING SPECIALISED CELLS IN DICOTYLEDONOUS PLANTS
- 1Using the Chart/diagram from the Science kit, show clear images of epidermal cells, guard cells, cambium, and xylem vessels. Point to each cell type and name it aloud while learners write the names and draw the shapes in their exercise books. Explain: Epidermal cells form a protective covering like a fence around the plant; guard cells are kidney-shaped and work in pairs to open and close tiny pores called stomata; cambium cells are small and active, helping the plant grow wider; xylem cells are tube-shaped and empty, designed to carry water upward.
- 2Ask learners to search in the Textbook for information about each of these four specialised plant cells and identify one key feature of each — for example, the thick wall of xylem or the chloroplasts in epidermal cells of some leaves. Working in pairs, learners complete a simple table in their exercise books with the cell name, its shape, and one feature they found. Pairs then compare tables with another pair to check accuracy.
- 3Challenge learners to examine the chart again and explain in one sentence why each cell's shape or structure is suited to its job — for example, the tube shape of xylem allows water to flow, or the kidney shape of guard cells allows them to squeeze open and closed. Volunteers share their sentence with the class.
- 4Struggling learners: provide a partially completed chart naming the cells and shapes already; they add only one feature per cell type with a word bank of suggestions (protection, water transport, growth, control).
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- 1Textbook
- 2Science kit/specimens
- 3Chart/diagram showing epidermal, guard, cambium, and xylem cells
- 4Exercise book
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- 1Learners stand in four groups, each assigned one specialised plant cell: epidermal, guard, cambium, or xylem. Each group discusses for 1 minute what would happen to a bean plant if that cell type stopped working. Group representatives share their ideas — for example, without guard cells, the plant would lose too much water through the leaf.
- 2Display the four cell images again and ask learners to point to or whisper the correct cell name as you describe its function: the cell that opens and closes stomata, the cell that carries water, the cell that protects the leaf, the cell that makes the stem grow thicker. Learners respond chorally to consolidate naming and function.
Exercise
- 1Look at the chart showing the four specialised plant cells. Name each cell type, describe its shape in one sentence, and explain how its shape helps it do its job in the plant. You may draw and label a diagram to support your answer.
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- 1Identify the names and shapes of specialised animal cells by observing them on pictures, videos, and charts.
- 2Show pictures or a video of nerve cells, blood cells, muscle cells, and sperm cells displayed on a chart or Science kit specimen image. Ask learners: Do these cells look like the plant cells we saw yesterday? What shapes do you notice — are any of them long and thin, or round, or have a tail? Learners discuss in pairs and point out the different shapes to activate prior knowledge of animal cell diversity.
- 3Ask learners: What job does a nerve cell do in your body? What job does a blood cell do? Learners whisper their ideas to their partner before sharing with the class. This prepares them to connect the shape of animal cells to their specific functions in the human body.
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- OBSERVING AND NAMING SPECIALISED ANIMAL CELLS
- 1Using the Chart/diagram or video, show clear images of four specialised animal cells and name each one aloud: nerve cells (long with branching ends), blood cells (round red cells and white cells with irregular shapes), muscle cells (long and striped), and sperm cells (tiny with a tail). Write each name on the board and ask learners to sketch the shape of each cell in their exercise books as they hear it described. Explain briefly: Nerve cells carry messages around the body like telephone wires; blood cells carry oxygen and fight infection; muscle cells contract to make the body move; sperm cells are designed to swim to an egg.
- 2Working in small groups, learners search the Textbook or use the Chart/diagram to find one function of each of the four animal cell types. Each group records the cell name and its function on paper. A representative from each group shares one cell and its function aloud. Write these on the board so the class can copy them into their exercise books alongside their sketches.
- 3Ask learners to make a simple model or drawing showing why each cell's shape is useful for its job — for example, draw a nerve cell with a long thin body that stretches from the brain to a finger, explaining how its length helps it send messages over a distance. Learners work in pairs to complete one detailed model or drawing with labels and share with another pair.
- 4Struggling learners: provide a table with cell names, shapes already drawn, and blanks for functions; they fill in only the function column using a word bank (carry oxygen, send messages, move the body, reproduce).
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- 1Textbook
- 2Science kit/specimens
- 3Chart/diagram showing nerve, blood, muscle, and sperm cells
- 4Exercise book
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- 1Learners stand and mime the function of one specialised animal cell — a nerve cell sending a signal, a blood cell delivering oxygen, a muscle cell contracting, or a sperm cell swimming. Other learners guess which cell is being acted out, then the actor names the cell aloud. This physical consolidation reinforces both the shape and function of animal specialised cells.
- 2Ask the class: How would a human survive if they lost all their nerve cells? What about muscle cells or blood cells? Learners raise their hands to respond, and discuss briefly how each specialised cell type is essential for human survival and health.
Exercise
- 1Choose one specialised animal cell (nerve, blood, muscle, or sperm). In your exercise book, write its name, describe its shape in one sentence, and explain how that shape helps it do its job in the human body. Draw a simple labelled diagram of your chosen cell to show the feature that makes it special.
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