The cells of a tumour double every 90 days…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
The cells of a tumour double every days. Use days for a year.
- How many years do doublings take, to one decimal place?
- How many whole doublings take place in years?
- How many cells are there after those whole doublings, if the tumour started from one cell?
Need a reminder? The key ideaShow
Normal cells stop dividing when they touch, which is contact inhibition. A malignant tumour invades and spreads by metastasis, and a benign tumour does not. After doublings, a tumour that grew from one cell has cells. Carcinogens may be physical, chemical or biological.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. One doubling every days. One year is days.
Plan. Change between doublings and days.
Step 1. Thirty doublings. days. years.
Step 2. Five years. days. , so whole doublings.
Step 3. The cells. cells.
Answer: years; doublings; cells.
Check. After doublings the tumour has about a million cells, which is far too small to feel. Ten more doublings take it to a billion.
Watch out. The doubling time of real tumours ranges from weeks to many months, and it changes with time.
Discussion (0)
Log in to join the discussion.
Loading…