How many rounds of mitosis are required to produce 1024 cells, starting with just one cell?

10 rounds

explanation: We start with one cell. A round of mitosis doubles the number of cells. 

After n rounds of mitosis, we have 2^(n) cells. After 10 rounds, we have 2^10 = 1024 cells. 

If you don't see this, just start with 1 and multiply it by 2 until you get 1024. You have to do this 10 times.