Investigating Cell Structures

Overview

Curriculum Area: Science – Biological Sciences
Year Level: Year 8
Australian Curriculum Code: AC9S8U01
Strand: Science Understanding – Biological Sciences
Content Description: Recognise cells as the basic units of living things, compare plant and animal cells, and describe the functions of specialised cell structures and organelles.
Elaboration Focus: Designing a physical or digital model of a cell and explaining how the representation models the cell.
Duration: 35 minutes
Class Size: 6 students
Lesson Type: Explicit Instruction
Cross-Curricular Priorities: Literacy, Numeracy

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Learning Intentions

By the end of this lesson, students will:

1. Recognise that cells are the building blocks of all living things.
2. Identify key organelles within plant and animal cells.
3. Understand the function of specialised cell structures.
4. Compare and contrast plant and animal cells using appropriate scientific vocabulary.
5. Begin to design a physical model of a cell using spatial and proportional reasoning (numeracy link).

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Success Criteria

Students will be successful when they can:

✅ Accurately name and locate major organelles in both plant and animal cells.
✅ Use scientific language to describe the function of at least 3 cell structures.
✅ Identify similarities and differences between plant and animal cells.
✅ Begin constructing a labelled physical model of a cell using correct proportions.

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Materials Needed

• Laminated diagram sets of plant and animal cells
• Whiteboard and markers
• Modelling materials (e.g., plasticine, pipe cleaners, beads, foam shapes)
• Rulers / measuring tapes
• Cell terminology cards
• Worksheets (comparison table + model planning sheet)
• Literacy word bank posters (visual scaffold)
• Numeracy conversion chart (mm to cm, proportion guides)

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Lesson Sequence

1. Warm-Up / Engage (5 mins)

Activity: Cell Mystery Box
Present a sealed box or bag with objects inside that represent organelles (e.g., a marble for the nucleus, a sponge for cytoplasm, rubber bands for cell membrane, etc.). Have each student blindly select one item and describe it using adjectives. Then link the adjective description to the function of the real organelle.

Purpose: Stimulates curiosity and primes students for describing functions and structures using literacy skills.

Teacher Talk:
"Cells are like mini-cities. Each part – or organelle – has a job to do. Let's discover what makes a plant or animal cell tick!"

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2. Explicit Teaching (10 mins)

Teaching Strategy: Direct Instruction using visuals, simplified scientific language, and verbal cueing.

Visuals:

• Show clear, labelled diagrams of plant and animal cells side-by-side on the board.
• Use colour-coded labels and shape symbols (triangle = nucleus, circle = chloroplast, etc.)

Focused Content:

• Cell Membrane
• Cytoplasm
• Nucleus
• Mitochondria
• Vacuole (noting size difference in plant cells)
• Chloroplast (in plant cells only)
• Cell Wall (plant cells only)

Pronunciation Practice (Literacy focus): Together say aloud the scientific words multiple times while pointing to them on the diagram. Use syllable clapping for longer words like 'mi-to-chon-dria'.

Numeracy Focus:
Use a simple proportional grid (1 grid square = 1 cm) on the board to show the relative sizes of organelles. Ask: "If the cell is 10 cm wide, how wide does the nucleus need to be to be in proportion?"

Checking For Understanding (Formative Assessment): Students complete a short matching task at their desks – match labels with organelle descriptions.

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3. Guided Practice (10 mins)

Activity: Compare & Contrast Table
Verbally guide students through completing a "Plant vs Animal Cells" comparison table (worksheet). Use think-aloud modelling:

Example Teacher Prompt: "Let’s think about the chloroplast – I know they make food using sunlight. Do both cell types need to do that?"

Literacy Strategy: Word scaffolds are provided for EAL and lower-literacy students, including sentence starters:

• "In both cells, we see..."
• "Only in plant cells, there is a..."
• "The function of the ___ is to..."

Numeracy Strategy: Discuss the proportion of space organelles take up in cells using fractions (e.g., chloroplasts make up ⅓ of the plant cell’s sunlight-processing area).

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4. Independent / Paired Activity (7 mins)

Activity: Start Your Model
Students begin designing a physical model of either a plant or animal cell using provided resources.

Task Instructions:

• Choose either plant or animal cell.
• Plan your model using the grid on the worksheet (1 cm = 1 mm in real cells).
• Create a basic 3D structure and label at least 3 organelles.
• Think about proportional spacing.

Support Provided:

• Visual planning templates
• Glossary sheet
• List of acceptable household modelling items (to complete for homework if needed)

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5. Wrap-Up / Reflection (3 mins)

Activity: Exit Ticket – 3, 2, 1
Write the following on a mini whiteboard:

• 3 organelles I can name
• 2 differences between plant and animal cells
• 1 question I still have

Students share with a partner or aloud if comfortable.

Extension/Homework Task: Students are to complete their physical model at home using household items and bring it in for presentation. They will also write a short explanation of how their model represents each organelle (literacy).

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Differentiation Strategies

Support:

• Sentence stems, labelled diagrams, and clear visuals for all learners.
• Word banks and mini-dictionary sheets.
• Supported oral rehearsal before any writing.
• Peer pairing for guided tasks.

Extension:

• Students create an analogy (“The Cell as a Factory”) and use metaphor to describe each structure.
• Numerical challenge: Estimate total surface area of a cell model based on dimensions used.

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Assessment Strategies

• Formative: Worksheet completion (accuracy and detail), verbal responses, whiteboard exit ticket.
• Summative: Cell model (clarity, accuracy, proportion) and the accompanying explanation text.

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Literacy & Numeracy Integration

Literacy Focus:

• Scientific vocabulary pronunciation and comprehension.
• Sentence construction using comparative language ("similar to", "only in").
• Written description of model parts.

Numeracy Focus:

• Using scale (1 cm = 1 mm) to design models.
• Estimating sizes and proportions of organelles.
• Basic fraction and spatial awareness when designing.

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Reflection & Feedback

After the lesson, note:

• Which students could articulate organelle function with clarity?
• Did all students understand the structural difference between cell types?
• How well did students use proportionality in their model design?
• Use this data to shape the follow-up or presentation lesson.

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This fast-paced yet deep-thinking lesson blends explicit instruction with visual, tactile, and verbal engagement – it empowers learners through age-appropriate challenges and connects clearly to Science, Literacy, and Numeracy frameworks in the Australian Curriculum (AC9S8U01).