At the end of prophase, spindle fibers form among the chromosomes, and the kinetochore of each chromatid becomes attached to which specific structure, formed by a spindle fiber?

Chromosomal Microtubule

Explanation:

Chromosomal microtubule are tiny hollow structure that appear tube-like under the microscope which are primarily made from cytoskeleton's proteins and beta tubulin. They are polar molecules formed by spindle fiber with fast growing positively charged end and slow-growing negative ends.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.