If you are provided with the root­ tips of an onion in your class and are asked to count the chromosomes, which of the following stages can you most conveniently look into?

Explanation

Metaphase is the best time to count and study the number and morphology of chromosomes. The distinctly visible chromosomes arrange themselves at the equatorial or metaphasic plate. The centromeres lie at the equatorial plate while the limbs are placed variously according to their size and spiral arrangement. At prophase, the chromosomes appear thin and filamentous, forming a network. So they are not very clearly visible. At telophase, the chromosomes uncoil and lengthen and therefore are not clearly seen. Anaphase also shows chromosomes distinctly and they can be counted. But during anaphase chromatids separate and start moving towards opposite poles. So metaphase is the best stage for counting.The order of visibility of the stages of mitosis under the microscope is as follows: Metaphase > Anaphase > Prophase > Telophase