Questions: Structures that extend from the kinetochore of each chromatid to the centrioles during mitosis are called - centromeres - pertcentriotar material - spindle fibers.

The answer is the third one (C): spindle fibers.

Explanation for each option:

• Centromeres: These are the regions on a chromosome where the two sister chromatids are held together. They do not extend from the kinetochore to the centrioles; rather, they are the attachment point for the kinetochore.

• Pericentriolar material: This is a component of the centrosome that surrounds the centrioles and is involved in microtubule nucleation. It does not extend from the kinetochore to the centrioles.

• Spindle fibers: These are structures made of microtubules that extend from the kinetochores on the chromatids to the centrioles (or centrosomes) during mitosis. They play a crucial role in separating the chromatids by pulling them toward opposite poles of the cell.

In summary, the structures that extend from the kinetochore of each chromatid to the centrioles during mitosis are spindle fibers.