Final answer:
The structure that forms in between an animal cell to separate its cytoplasm during cytokinesis is called the cleavage furrow.
Step-by-step explanation:
The structure that forms between an animal cell to separate its cytoplasm during cytokinesis is called the cleavage furrow. It is a contractile band made up of microfilaments, primarily composed of actin, that forms around the midline of the cell.