Human cells grown in culture divide about once every 24 h.
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Human cells grown in culture divide about once every . Yeast can go through its cell cycle in about . Take every cell to divide on time.
- A culture starts with human cells. How many cells are there after ?
- A culture starts with one yeast cell. How many cells are there after ?
- One cell and all its descendants divide by mitosis until there are cells. How many rounds of division does this take, and how many cell divisions take place in all?
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.
(a) Human cells. cycles, so the number doubles times: cells.
(b) Yeast. , which is cycles: cells.
(c) Rounds and divisions. , so rounds are needed. Every single division turns one cell into two, adding one cell. Going from cell to cells needs divisions ().
Answer: (a) cells. (b) cells. (c) rounds and divisions.
Check. In (c), the divisions round by round are and ; their sum is , one less than the final number of cells.
Watch out. "How many divisions" and "how many rounds" are different questions. A round doubles every cell at once; a division is one cell splitting into two.
More onCell Biology
Discussion (0)
Log in to join the discussion.
Loading…