Answer:
A
. centrioles; spindle fibers
Explanation:
1. Centrioles are a cell organelle present in all animal cells in pair. In plant cells, centrioles are present in the male gametes of ginkgo, cycads, and bryophytes. They are normally present near the nucleus but can be seen only when the cell is dividing. Centrioles are made of a set of three microtubules. The microtubule is made of tubulin protein. Centriole forms and organize spindle fibres during cell division.
2. Spindle fibres are filaments which are formed during mitosis and meiosis. They are made up of microtubules and formed by centrioles. Spindle fibres formed at opposite poles of the cell and meet at the equatorial plane. They arranged like a spindle-shaped structure, so they named as spindle fibres. They help in moving and separating the chromosomes during cell division.
