Meiosis and Mitosis
This will tell you about the differences between them.
In order for a cell to divide the original NA inside the cell must first make a copy of itself.
So looking at the picture I will explain what happens. In the first and second picture the parent DNA cells are starting to unzipping, the bases are split apart. In the third picture the unzipped halves of DNA stand, they act as a template to form a new DNA strand. In the last two pictures the two copies made containing half original DNA and half newly made DNA.
For the first image you call it: Parent DNA
For the second image you call it: Stepl unzipping.
For the last two images you call them the daughter DNA molecules.