The spindle apparatus of animal cells centers on a cell structure called the chromatid centromere centriole mitochondria

Correct D) Centrioles

A centriole is a cylindrical shaped organelle , which is made up of composed  of tubulin protein. They are found in the eukaryotic cells.

It is found as a paired structure in the centrosome. The centrioles are made of bundles of microtubules.

The position of centriole determine position of nucleus. It play an important role in the cell division. The main function of centrioles is to help in cell division in animal cell. They help in formation of spindle fibers that are used to separate the chromosome during the cell division.

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