Science lesson plan · 9th grade (Year 10 in England) · 45 minutes
The cell cycle and the stages of mitosis
Cells, genetics and evolution
CCSS NGSS.HS-LS1-4England: GCSE Combined Science: Cell biology
Objective and success criteria
Students will: The cell cycle and the stages of mitosis.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Mitosis and meiosis
Leads to: the next skill in this area.
Materials: Microscope images or slides, Cell diagrams, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Mitosis and meiosis). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Mitosis or meiosis? It used in asexual reproduction. (mitosis / meiosis) → mitosisPrompt: Which one makes sex cells (gametes)?
- A bacterium divides into two every 60 minutes. Starting with one cell, how many cells are there after 3 hours (if none die)? → 8Prompt: How many divisions happen in that time?
- What is an advantage of sexual reproduction? (It produces variation, which helps a species survive changes / It makes identical offspring / It is faster than asexual reproduction / It needs only one parent) → It produces variation, which helps a species survive changesPrompt: Mixing genes from two parents makes offspring different.
Hook · 5 min
- Show a microscope image of cells and ask what students think they are looking at.
- Share the objective: The cell cycle and the stages of mitosis. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: A cell is seen with chromatids moving to opposite ends. Which stage?
- Step 1: In anaphase, spindle fibres pull the chromatids apart.
- Step 2: So the answer is: anaphase
- Answer: anaphase
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Under the microscope, chromosomes are lined up across the centre of a cell. Which stage is this? (interphase / anaphase / metaphase / prophase) → metaphasePrompt: "Meta" sounds like "middle".
- In a root tip slide, 300 cells were counted. 45 of them were dividing. The cell cycle takes 30 hours. Estimate how long mitosis lasts, in hours. → 4.5 hPrompt: The fraction of cells in mitosis equals the fraction of time spent in mitosis.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- In a root tip slide, 360 cells were counted. 54 of them were dividing. The cell cycle takes 36 hours. Estimate how long mitosis lasts, in hours. → 5.4 hPrompt: The fraction of cells in mitosis equals the fraction of time spent in mitosis.
- Why must DNA be copied during interphase? (To halve the chromosome number / So the cell can photosynthesise / So each new cell gets a full, identical set of chromosomes / To make gametes) → So each new cell gets a full, identical set of chromosomesPrompt: Mitosis makes two identical cells.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Mitosis and meiosis.
- Use concrete materials: microscope images or slides.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-9.
Free lesson plan from eurekami.com/lesson-plan-builder