Question
Biology Question on cell cycle and cell division
In onion root tip during metaphase stages mitosis the number of kinetiochores will be
A
4
B
8
C
16
D
32
Answer
32
Explanation
Solution
Metaphase is the best time to count the number and study the morphology of chromosomes. At metaphase, the condensed chromosomes with two chromatids are
arranged at the equatorial plate. Kinetochore, consisting of multilayered plates of proteins, forms on opposite sides of each centromere and becomes intimately associated with the two sister chromatids. In onion root tip, each somatic cell contains 8 chromosomes. A cell undergoing cell division has duplicated its chromosomes thus a cell at metaphase stage of cell division has 16 chromosomes. As each chromosome has two kinetochores thus during metaphase 32 kinetochores can be seen.