Final answer:
During mitosis in animal cells, the centrosome containing centrioles is utilized alongside the spindle apparatus to organize cell division.
Step-by-step explanation:
The organelle that is utilized during mitosis in animal cells alongside the spindle apparatus is the centrosome, which contains a pair of centrioles. The centrioles help organize cell division by forming the spindle fibers that are necessary to separate chromosomes during mitosis. In plant cells, which generally lack centrioles, this function is taken over by the microtubule organizing centers (MTOCs). However, in animal cells, the presence of centrioles associated with the MTOC, a complex known as the centrosome, is a key feature distinct from plant cells.