$DNA$ replication occurs in .........

Arrange these events of mitosis in their correct sequence:
$a -$ Nuclear envelope assembles around chromosome clusters.
$b -$ Spindle fibers attach to kinetochores of chromosomes.
$c -$ Condensation of chromosomes.
$d -$ Centromeres split and chromatids separate.

When radioactive thymine is added to the medium during the synthesis of new $DNA$ in human cells,which of the following chromatids will become radioactive in cells that enter the phase immediately upon contact with radioactive thymine?

Karyokinesis $= P$
Cytokinesis $= Q$
Select the correct option for $P$ and $Q$.
$P$ and $Q$ are respectively:

Select the correct option by matching Column $I$ with Column $II$.

Column $I$	Column $II$
$A$. Synapsis aligns homologous chromosomes	$(i)$ Anaphase $II$
$B$. Synthesis of $RNA$ and protein	$(ii)$ Zygotene
$C$. Action of enzyme recombinase	$(iii)$ $G_2$ phase
$D$. Centromeres do not separate but chromatids move towards opposite poles	$(iv)$ Anaphase $I$
	$(v)$ Pachytene

Mitosis and meiosis take place respectively in