Rodney Dority, age 14, of Darlington, S.C., for his question:

WHAT IS MITOSIS?

Mitosis is a process by which most cells divide. First a cell will divide and form into two identical daughter cells. Each daughter cell then doubles in size and becomes capable of dividing. Most one celled plants and animals reproduce by the process of mitosis.

Mitosis is also the way most cells in your body and in many celled plants and animals reproduce. In animal cells there are four orderly stages: a prophase when chromosomes duplicate themselves, a metaphase when the chromosomes move to the middle of the cell, the anaphase when the sister chromosomes separate and move to opposite poles and the telophase when the cell splits at the equator. Two new cells are then produced with each having a full set of chromosomes and the same hereditary information as the original cell.