Mitosis and Growth

Overview

Students model and explain mitosis as a key process in organism growth and repair. They will observe a short video and use hands-on tools (stage cards and a simple “cell cycle” model) to sequence mitosis stages and describe what happens to chromosomes.

Learning intentions

• Students will be able to explain the purpose of mitosis in multicellular organisms.
• Students will be able to describe the main stages of mitosis in the correct sequence.
• Students will be able to connect cell division to growth and tissue repair.
• Students will be able to use a model to show how chromosomes are copied and separated.

Success criteria

• I can describe what mitosis does for an organism (growth and repair).
• I can order and name the stages of mitosis.
• I can explain how chromosomes are handled during each stage using the model.
• I can use scientific language (chromosomes, nucleus, cell, spindle fibres) in my explanation.

Curriculum links

• Observable patterns of cell growth and division in living things, including the role of cell division in organism growth and repair.
• Understanding organelles and how cellular structures are involved in processes such as cell division.
• Using models and evidence to explain biological processes (reasoning with cause-and-effect).

Lesson structure (45 minutes)

1. 2 min — Activate knowledge

• Quick prompt: “Why do multicellular organisms need more cells as they grow?” Students turn-and-talk, then share one idea as a class.

2. 6 min — Mini lesson with anchor image

• Show an annotated diagram of mitosis stages. Briefly connect to the idea that cells must produce new cells for growth and repair.
• Teacher explicitly names: chromosomes, nucleus, and “new identical cells” (no heavy jargon beyond student-friendly definitions).

3. 9 min — Video observation (with guided notes)

• Students watch a short mitosis video. Provide a simple worksheet with three tasks: list the stage names you hear, sketch one key event, and note any tricky vocabulary they need help with.
• Pause once for “What changed in the nucleus?” and once for “How do chromosomes end up separated?”

4. 10 min — Hands-on modelling: stage sequencing

• In groups of 3–4, give each group a set of mitosis stage cards and a simple “chromosome” model (e.g., paper strips or bead strings representing chromosomes, plus a paper circle for the nucleus).
• Students arrange cards in order and justify their order using stems: “I think stage ___ comes next because ___.”
• Teacher circulates, checking for correct sequencing and language.

5. 10 min — Hands-on modelling: building a full mitosis cycle

• Groups rebuild the cycle using physical movements: “start” (nucleus containing replicated chromosomes), then separate into two groups, then form two new nuclei/cell halves.
• Students complete a one-page “model explanation” linking each stage to what happens to chromosomes.

6. 6 min — Whole-class debrief and corrections

• Using a projector, select one group’s sequence and class-correct common misconceptions (for example, confusion between cell division and DNA copying, or forgetting that the product is two genetically identical cells in mitosis).
• Students add missing stage labels to their own notes.

7. 2 min — Exit ticket (evidence of learning)

• Exit ticket: “Explain, in 3–5 sentences, how mitosis helps an organism grow or repair tissue. Include the correct stage names in your explanation.”

Resources

• Mitosis stage cards (numbered and labelled) for small groups
• Simple chromosome model materials (bead strings, paper strips, or magnetic shapes)
• Paper templates: nucleus circle and cell boundary
• Slide/print diagram of mitosis stages
• Short teacher-selected video demonstrating mitosis
• Guided video notes sheet with sentence starters
• Exit ticket slips
• Whiteboard markers/chalk and student science notebooks
• Visual word bank (chromosome, nucleus, spindle fibres, cell division, growth, repair)

Assessment

• Formative: teacher checks group sequencing and listens for student justifications during stage modelling.
• Formative: guided video notes for key events and vocabulary needs.
• Summative (quick): exit ticket evaluates correct stage order, mitosis purpose, and accurate chromosome descriptions.

Differentiation

• Support (ESL/EAL): provide sentence frames for the modelling justification and exit ticket (e.g., “In stage __, chromosomes ___. This is important because ___.”); include an illustrated word bank with student-friendly definitions.
• Support (SEN): offer a partially completed stage sequence diagram for students who need reduced demand; allow verbal responses to be recorded in a teacher-approved template.
• Extension: challenge early finishers to add an “evidence sentence” for each stage (what in the model/video shows that stage) and explain why mitosis is different from other types of cell division in one comparison sentence.
• Language scaffolds: allow students to use first-language supports during group planning, then require final answers in English using the provided frames and stage labels.

Unit/lesson breakdown (long-range plan)

• Unit goal: Students investigate how cells work and how their structures support life processes, culminating in explaining how cells grow and divide.
• Progression across lessons (15 total):
• Lessons 1–3: Cell structures and organelles; compare plant and animal cells; use microscopy-based ideas (conceptual models).
• Lessons 4–6: Cell processes (transport and exchange) and how substances move in/out.
• Lessons 7–9: Cellular energy needs and basic process models (building understanding of cause-and-effect).
• Lessons 10–11: Cell division introduced; Lesson 11 focuses on mitosis (stages, sequencing, and significance).
• Lessons 12–15: Cell division consequences and applications—linking mitosis to growth/repair, addressing common misconceptions, and consolidating with model-based explanations and/or mini investigations.
• Where Lesson 11 fits:
• Students already know that cells are the basic unit of life and that organisms grow by increasing cell number.
• Lesson 11 provides the mechanism (mitosis) and the “why” (growth/repair), building readiness for later lessons that deepen comparisons and applications.