Cells Make Life Possible

Overview

This is Day 1 of a 30-day sequence on Cells as the Basis of Life. Students activate prior knowledge and investigate why cells are considered the fundamental units of living things, comparing common features and differences between prokaryotic, plant, animal and specialised cells.

Learning intentions

Students will:

• explain why cells are regarded as the basic units of life
• identify structures shared by most cells and describe their functions
• compare prokaryotic and eukaryotic cells, including plant and animal cells
• construct a scientifically accurate explanation using evidence and biological terminology

Success criteria

• I can identify structures found in cells and state their functions.
• I can distinguish between prokaryotic and eukaryotic cells.
• I can explain how at least two cell structures support life processes.
• I can use observations from models or images as evidence in a biological explanation.

Curriculum links

• Cells as the basis of life: explaining how cell structures enable biological processes needed for life
• Cells and their environments: recognising the relationship between cell structures and survival
• Cells to systems: beginning to connect specialised cell structure with function
• Working scientifically: questioning, analysing information, constructing explanations and communicating findings

Lesson structure (50 minutes)

1. 0–5 min · Hook: What counts as alive? Teacher displays a microscopic image of bacteria, a cheek cell and a plant cell using the opening mystery images and asks, “What do these have in common, and how could we know they are living?” Students write an individual response, then share one idea with a partner.

2. 5–12 min · Establish the big idea. Teacher introduces the statement “Cells are the basis of life” and explains that life processes, including obtaining materials, releasing energy, removing wastes, responding and reproducing, depend on activity within cells. Students annotate the cells-as-life-foundation worksheet by completing a concept map linking “cell” to three life processes.

3. 12–22 min · Direct teaching: common structures. Teacher uses labelled diagrams in the cell structures teaching sequence to review the cell membrane, cytoplasm, genetic material and ribosomes, then introduces the nucleus, mitochondria, chloroplasts and cell wall as structures found in particular eukaryotic cells. Students complete a two-column table on the worksheet: “structure” and “how it supports life”.

4. 22–32 min · Compare cell types. Teacher models how to compare cells by structure and function, using the prokaryote, animal cell and plant cell diagrams in the comparison diagrams. In pairs, students complete a Venn-style comparison on the worksheet, identifying shared structures and features that distinguish prokaryotic, plant and animal cells. They must include one similarity and two differences.

5. 32–42 min · Evidence challenge: structure and function. Teacher presents three unfamiliar cell images or diagrams in the evidence challenge: a bacterium, a photosynthetic plant cell and a muscle cell. Students infer the likely function of each cell and justify one inference using visible or described structures. Pairs use the sentence frame “The presence of ___ suggests ___ because ___.” Selected pairs share answers; the teacher corrects misconceptions, including that cells do not all contain the same organelles and that plants also respire.

6. 42–47 min · Individual explanation. Teacher asks students to answer the worksheet question: “Explain why a cell is considered the basic unit of life. Refer to two structures and the processes they support.” Students write independently, using at least three terms from the lesson. Teacher circulates, checking for accurate links between structure and function.

7. 47–50 min · Exit check and preview. Teacher displays the three-question plenary in the exit check and next-lesson preview. Students submit responses: one shared cell feature, one structure-function relationship and one question they still have. Teacher previews Day 2, which will develop microscopy, scale and cell diversity.

Resources

• the cell structures and comparison slide deck
• the cells-as-life-foundation worksheet
• Projector or interactive display
• Whiteboard and markers
• Microscopic images or cell diagrams
• Student exercise books
• Coloured pens or highlighters

Assessment

• Questioning during the hook and direct teaching checks prior knowledge and identifies misconceptions.
• Pair comparison and evidence challenge responses assess whether students can distinguish cell types and connect structures with functions.
• The individual explanation and exit check provide evidence of conceptual understanding, scientific vocabulary and ability to justify an idea.

Differentiation

• Provide a labelled word bank, partially completed comparison table and sentence frames for students requiring support, including EAL/D learners.
• Read instructions aloud, use high-contrast diagrams and allow students to respond in labelled diagrams before writing extended explanations.
• Pair students strategically and assign roles such as reader, recorder and evidence checker.
• Challenge confident students to explain how a specialised cell’s structure is suited to its function, or to identify a limitation of using a two-dimensional cell diagram as a model.