The answer is <span>a. kinetochore.
A kinetochore is a protein structure that holds the </span><span>sister chromatids to the spindle fibers. It is the place on chromatids where the spindle fibers bind during the cell division. As the result, sister chromatids are pulled apart to the opposite ends of the cell.</span>
Because they are good at their professions
The homologous structures and the analogous structures of different species.
