How does E. Mulsion, celebrity food scientist, define a physical reaction and what examples does he give?

Incomplete question. However, I assumed you are referring to the comments made in the online animated video (Chemical and Physical changes)  by celebrity food scientist E. Mulson.

Explanation:

Recall in the video animation that E. Mulson defines physical reaction as occurring when "molecules in a substance stay the same, both before and after".

An example he gave was that of an orange getting juiced, the molecules remain the same before juicing, and after.

cytokinesis is the splitting of a cell membrane to form 2 identical daughter cells. it's similar to mitosis as both cells have identical copies of dna and cytokinesis is a step in the mitotic cycle.