mitosis indication on given picture?

Ok so the question is:
On the drawing of a longitudinal section of a root shown below (attached image), indicate the region of the root in which you see cells undergoing mitosis. Also indicate on the drawing where the youngest and oldest tissues are found.
We haven't really covered mitosis/meiosis in lecture so it's difficult for me to locate where these processes are occuring. I know mitosis involves the division of the nucleus to create two identical nuclei, but how would i identify this on the photo. Also how am i  supposed to know the differences between youngest and oldest tissues?