At which stage does the number of homologous chromosomes become halved?

Describe various subphases of prophase - $I$ of Meiosis - $I$.

Given below are two statements:
Statement $I$: Chromosomes become gradually visible under light microscope during leptotene stage.
Statement $II$: The beginning of diplotene stage is recognized by dissolution of synaptonemal complex.
In the light of the above statements,choose the correct answer from the options given below:

The simultaneous splitting of the centromere of each chromosome allowing them to move toward opposite poles of the cell is a change shown in......

In which stage of meiosis do the sister chromatids of two cells move towards opposite poles via spindle fibers?

Into how many sub-phases is Prophase-$I$ divided?