1. Recall
When is DNA copied: interphase or mitosis?
Help beside the question
Read or point first. Preparation comes first.
Answer guidance
Interphase.
Mitosis: read the chromosome evidence
Learning objective
Sequence prophase, metaphase, anaphase and telophase using visible chromosome evidence.
40 minutes · one route · start from what you show today. Point, speak, sign, draw, write or direct an adult. An adult may read or scribe your exact words. Choose one route; do not complete all three.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 4 MINUTES
Four clues to start
Supported · 4 questions
2. See
Chromosomes are lined up in the middle. Which stage is this?
Help beside the question
Read or point first. Use the word bank: metaphase / telophase.
Answer guidance
Metaphase.
3. Distinguish
What separates in anaphase?
Help beside the question
Read or point first. Look at the joined copies of a chromosome.
Answer guidance
Sister chromatids separate; each becomes a chromosome.
4. Count
A model parent has 4 chromosomes. How many should each daughter cell receive?
Help beside the question
Read or point first. Each needs a complete matching set.
Answer guidance
4 chromosomes.
Standard · 4 questions
1. Recall
When is DNA copied: interphase or mitosis?
Help beside the question
Preparation comes first.
Answer guidance
Interphase.
2. See
Chromosomes are lined up in the middle. Which stage is this?
Help beside the question
Use the word bank: metaphase / telophase.
Answer guidance
Metaphase.
3. Distinguish
What separates in anaphase?
Help beside the question
Look at the joined copies of a chromosome.
Answer guidance
Sister chromatids separate; each becomes a chromosome.
4. Count
A model parent has 4 chromosomes. How many should each daughter cell receive?
Help beside the question
Each needs a complete matching set.
Answer guidance
4 chromosomes.
Stretch · 4 questions
1. Recall
When is DNA copied: interphase or mitosis?
Help beside the question
Preparation comes first.
Answer guidance
Interphase.
2. See
Chromosomes are lined up in the middle. Which stage is this?
Help beside the question
Use the word bank: metaphase / telophase.
Answer guidance
Metaphase.
3. Distinguish
What separates in anaphase?
Help beside the question
Look at the joined copies of a chromosome.
Answer guidance
Sister chromatids separate; each becomes a chromosome.
4. Count
A model parent has 4 chromosomes. How many should each daughter cell receive? Give a reason.
Help beside the question
Each needs a complete matching set.
Answer guidance
4 chromosomes. Accept a scientifically correct reason that uses the relevant model or evidence.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 4 MINUTES
Choose a first idea
Which is evidence for anaphase?
Think or discuss first. No answer chosen yet.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 5 MINUTES
Watch the model
During interphase the cell grows and copies its DNA. Each replicated chromosome has two joined sister chromatids.
Worked explanation · reveal after thinking
This schematic uses four chromosomes, not the human number. A replicated X is one chromosome with two sister chromatids. After chromatids separate, each is a chromosome. DNA copying does not mean each daughter cell has twice the chromosome number. The full cycle includes interphase, mitosis and cytokinesis. Interphase chromosome symbols show DNA copies schematically; the chromosomes are not normally visibly condensed at this stage.
32-second silent captioned explainer · optional
No sound or autoplay. Use instead of part of the modelling time, not as an extra activity.
Full transcript
Prepare and copy. During interphase the cell grows and copies its DNA. Each replicated chromosome has two joined sister chromatids.
Line up. During metaphase the replicated chromosomes line up at the centre of the cell.
Separate copies. During anaphase sister chromatids separate. One copy of each chromosome moves to each end.
Divide the cell. Nuclei reform and the cytoplasm divides. Two daughter cells each receive the same chromosome set.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 5 MINUTES
Sort using the evidence
Choose a card, then choose a group. Explain one placement using its clue.
Drag, or use Tab and Enter to select a card and its group. Pointing or adult-directed placement works too.
Before separation
Separation
Nuclei reform
Choose a card first.
Read the card clues
Chromosomes condense: Prophase makes chromosomes easier to see.
Nuclear membrane breaks down: This happens during early mitosis.
Chromosomes line up centrally: Metaphase comes before separation.
Sister chromatids move apart: Anaphase sends one copy to each pole.
Two complete sets at opposite ends: The sets have reached the ends as telophase begins.
Nuclear membranes reform: Telophase forms two nuclei.
Would a small change help? · optional
Ask the lesson teacher for clearer labels, fewer cards, reading help, an adult-directed model or more thinking time. Your teacher will explain what can change, try it and check its effect. Ask privately or pass; no extra form is needed.
Group explanations · reveal after sorting
Chromosomes condense → Before separation. Prophase makes chromosomes easier to see.
Nuclear membrane breaks down → Before separation. This happens during early mitosis.
Chromosomes line up centrally → Before separation. Metaphase comes before separation.
Sister chromatids move apart → Separation. Anaphase sends one copy to each pole.
Two complete sets at opposite ends → Nuclei reform. The sets have reached the ends as telophase begins.
Nuclear membranes reform → Nuclei reform. Telophase forms two nuclei.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 4 MINUTES
Work through one example
Worked example
A picture shows four replicated chromosomes across the cell centre. Identify the stage from evidence.
Step 1
Describe first: the chromosomes are aligned centrally.
Step 2
Compare with the stage descriptions, not just the order of letters.
Step 3
Central alignment identifies metaphase.
Step 4
Copies moving towards poles would instead support anaphase.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 4 MINUTES
Unlabelled cell models and observations
Cards P, Q, R and S describe a cell. Put them in order and give the evidence, not just a remembered letter sequence.
| Card | Visible observation |
|---|---|
| P | Two nuclear membranes are reforming |
| Q | Chromosomes have condensed |
| R | Chromosomes line up across the centre |
| S | Chromosome copies are moving to opposite poles |
Worked explanation · reveal after thinking
Q → R → S → P: prophase, metaphase, anaphase, telophase. Interphase happens before Q; cytokinesis completes division after nuclear separation.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 10 MINUTES
Show your understanding
Supported · choose one route
1. Order
Order P, Q, R and S from the evidence table.
Match each observation to a model card. Put the letters in boxes: ___ → ___ → ___ → ___.
2. Justify
Choose two neighbouring stages and explain the visible change.
Point to the chromosomes. Say: first I can see ___; in the next stage I can see ___.
3. Label
Add interphase and cytokinesis to the outside of your sequence.
Use two extra labels: interphase / cytokinesis. Place one before PMAT and one after nuclear division.
Standard · choose one route
1. Order
Order P, Q, R and S from the evidence table.
Locate condensation, alignment, separation and re-forming nuclei.
2. Justify
Choose two neighbouring stages and explain the visible change.
Use “First I can see… then…”.
3. Label
Add interphase and cytokinesis to the outside of your sequence.
These are part of the cycle but are not names in PMAT.
Stretch · choose one route
1. Order
Order P, Q, R and S from the evidence table.
Locate condensation, alignment, separation and re-forming nuclei.
2. Justify
Choose two neighbouring stages and explain the visible change.
Use “First I can see… then…”.
3. Evaluate a picture
A static image shows chromosomes at opposite ends but no new nuclei. Why might stage identification be uncertain?
Mitosis is continuous; textbook stages are descriptions.
LAUNCH · GCSE BIOLOGY FOUNDATION · W9 · LESSON 2 · 4 MINUTES
Two small checks
Supported · 2 questions
1. Evidence
Name the stage where chromosomes line up at the centre.
Help beside the question
Use: my answer is ___ because ___. Point to a model or card first. Describe the position, then name the stage.
Answer guidance
Metaphase.
2. Order
What follows anaphase, and what happens to the nuclei?
Help beside the question
Point or arrange first. Use: first ___, then ___, finally ___. Use the final mitosis stage.
Answer guidance
Telophase; new nuclear membranes form around the chromosome sets.
Standard · 2 questions
1. Evidence
Name the stage where chromosomes line up at the centre.
Help beside the question
Describe the position, then name the stage.
Answer guidance
Metaphase.
2. Order
What follows anaphase, and what happens to the nuclei?
Help beside the question
Use the final mitosis stage.
Answer guidance
Telophase; new nuclear membranes form around the chromosome sets.
Stretch · 2 questions
1. Evidence
Name the stage where chromosomes line up at the centre.
Help beside the question
Describe the position, then name the stage.
Answer guidance
Metaphase.
2. Evaluate a picture
A static image shows chromosomes at opposite ends but no new nuclei. Why might stage identification be uncertain?
Help beside the question
Mitosis is continuous; textbook stages are descriptions.
Answer guidance
It may be late anaphase or early telophase. The observation is secure, but the exact label needs clearer nuclear-membrane evidence.
Keep one useful science explanation. No additional participation record is required.