Mitosis and meiosis take place respectively in

For a cell,$n \rightarrow 2n$ $(P)$ and $2n \rightarrow n$ $(Q)$. What are $P$ and $Q$?

Which of the following does not occur during interphase?

Analogy type questions:
$(1)$ Human cells : Divide once in $24$ hours :: Yeast cells : .......
$(2)$ Nuclear division : Karyokinesis :: Cytoplasmic division : .......

During which phase$(s)$ of the cell cycle does the amount of $DNA$ in a cell remain at the $4C$ level,if the initial amount is denoted as $2C$?

Name the stage of the cell cycle at which the following events occur:
$(i)$ Chromosomes are moved to the spindle equator
$(ii)$ Centromere splits and chromatids separate
$(iii)$ Pairing between homologous chromosomes takes place
$(iv)$ Crossing over between homologous chromosomes takes place