Question

4. From what structures do the spindles originate?

Answer 1

The spindles in mitosis originate from the centrosomes and are involved in chromosome movement and cell division.

Step-by-step explanation:

The spindles in mitosis originate from the centrosomes.

During prophase of mitosis, the centrosomes, which are comprised of a pair of centrioles, begin to move apart and extend microtubules from each centriole. These microtubules form the mitotic spindle, which is involved in chromosome movement and cell division.

Specifically, the kinetochore microtubules attach to the kinetochores on the centromeres of the sister chromatids. This attachment allows for the proper alignment and segregation of chromosomes during mitosis.

Answer 2

The spindle fibers form out of the centrosome, also known as the microtubule-organizing center, or MTOC. Spindle fibers are formed from microtubules with many accessory proteins which help guide the process of genetic division. The spindle fibers form during cellular division near the poles of the dividing cell.
So basically i believe it originates from the centrosome.