The Cell That Wouldn't Stop
The Cell That Wouldn't Stop
In 1951, doctors took cells from Henrietta Lacks, a patient with cervical cancer. These cells, known as HeLa cells, became immortal - they continued dividing indefinitely in laboratory conditions. While normal cells have built-in controls that limit their division, cancer cells have lost these controls. Today, HeLa cells are still used in research worldwide, helping scientists understand cancer and develop treatments.
Cancer affects millions of people globally and represents one of biology's most complex challenges - understanding how normal cell division control breaks down.
Biology glossary
- What is cancer?
- Cancer is a group of diseases involving uncontrolled cell division, where cells divide continuously without normal restrictions.
Remember from topic-4 (Mitosis) that healthy cells have strict controls:
Earn the mark scheme marks
Memory Aids for Cancer Risk Factors
Use "BUMS" to remember the main carcinogen categories:
- B — Burning (UV radiation from the sun causes skin cancer)
- U — Unhealthy diet (high fat, low fibre, excess alcohol)
- M — Mutagens (chemical carcinogens such as asbestos, benzene)
- S — Smoking (tobacco smoke contains 70+ known carcinogens)
Alternative concept hook:
"Cancer = Cell Anarchy — No Controls, Everyone Replicates"
This reminds you that cancer is the breakdown of the normal rules governing cell division: checkpoints fail, oncogenes drive constant replication, and tumour suppressor genes no longer provide control.
Oncogene vs Tumour Suppressor — the Car Analogy:
- Proto-oncogene = accelerator pedal. Works normally until mutated into an oncogene (accelerator stuck down).
- Tumour suppressor gene = brake pedal. Works normally until mutated (brakes fail).
- Cancer = accelerator stuck + brakes gone. Uncontrolled speed.
Now try it yourself
Quiz · Question 1 of 20
In a healthy cell, cell division is controlled by:
Tap an answer to check it