During meiosis $I$,the chromosomes start pairing at

Crossing over occurs at the . . . . . . stage.

What is the number of chromatids in each chromosome during synapsis?

Which of the following stages of meiosis involves division of the centromere?

Identify the stage of meiosis characterized by the following features:
- Marked by terminalisation of chiasmata.
- Chromosomes are fully condensed.
- By the end of this stage,the nucleolus disappears.

In which stage does the process of crossing over occur?