In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant. 

Prophase, the chromosomes become visible. Centrioles separate to move to opposite poles. Metaphase, the chromosomes line up in the center. Anaphase, the chromatids separate. Are pulled apart. Telophase, the chromosomes gather at opposite poles. Two new nuclear membranes form. The cell membranes pinch. Divide into two individual cells. 
chromosome ,centriole ,spindle fiber ,chromatid ,nuclear membrane 