In a cell cycle, which structures serves as the site of attachment of spindle fibres?
a)	Chromosomes	b)	Histone	c)	Chromonemeta	d)	Kinetochore

(d)

Small disc-shaped structure at the surface of the centromeres are called kinetochores. These structures serve as the sites of attachment of spindle fibres (formed by the spindle fibres) to the chromosomes that are moved into position at the centre of the cell

Hence, the metaphase is characterized by all the chromosomes coming to lie at the equator with one chromatid of each chromosome connected by its connected by its kinetochore to spindle fibres from one pole and its sister chromatid connected by its kinetochore to spindle fibres from the opposite pole