Lesson 8: Factors Affecting Cell Division Rates & Cancer Biology
Use simulated tissue evidence to explain how direct and indirect resource availability affects cell division.
60-minute plan: retrieval 5 · evidence briefing 10 · dataset task 25 · portfolio 15 · exit check 5
🎯 Ngā Whāinga Akoranga | Learning Intentions
How direct resource availability and indirect factors such as temperature, signalling or delivery affect the rate of cell division.
Calculate mitotic index from a simulated tissue dataset and build a cautious causal explanation of observed differences.
📊 Evidence anchor: what does a mitotic index show?
The former video repeated Lesson 7 and did not supply evidence about division rates. This lesson now begins with the actual decision tool:
Mitotic index = number of cells visibly in mitosis ÷ total cells counted.
A higher index means a larger proportion of sampled cells were visibly dividing at that moment. It does not, by itself, prove that each mitotic event happens faster.
Immediate task: open Learner Evidence Pack · Sheet 8 and predict the ranking before calculating.
⚡ Whakaoho | Do Now: Cell Recall Challenge (5 mins)
Same organism, different rates. Rank a root tip, a mature leaf and a healing wound by expected cell-division activity. Give one biological reason for each position.
📖 Activity 1: Core Process Investigation & Diagram Analysis (25 mins)
Calculate and rank (12 min). Calculate mitotic index for every sample in the supplied simulated dataset. Compare the result with your prediction and cite the numbers.
Direct or indirect? (13 min). Sort the supplied factors, then explain how one direct resource and one indirect factor could change the observed index through resource supply, enzyme activity or cell-cycle control.
Supplied inputs
- Learner Evidence Pack · Sheet 8 — simulated tissue counts and factor sort
- Kaiako Guide · Lesson 8 — calculation, factor and health-context cautions
📝 Activity 2: Portfolio evidence (15 mins)
Complete Portfolio Section 8. For the 5-minute exit check, explain one limitation of using mitotic index as a measure of division activity.
🏫 Kaiako Planning & Pedagogy Notes
Level 2 Biology focus: use the current direct/indirect resource-availability framing. If cancer or chemotherapy is discussed, keep claims general and acknowledge that tumour types, treatments and responses differ. See Kaiako Guide · Lesson 8.
Paired concept in Mechanism & Exam Synthesis: mitosis & division rates →