Identify $A$ and $B$ respectively.

Chromonemata start associating into bivalent chromosomes during

The number of cells produced by meiosis is ..........

$A -$ During the formation of reproductive cells,meiotic cell division occurs.
$R -$ During meiosis,the genetic material is replicated twice and the cell divides twice.

When the number of chromosomes is already reduced to half in the first reductional division of meiosis,what is the necessity of the second meiotic division?

Match the following columns $I$ and $II$ correctly:

Column $I$	Column $II$
$A$. Leptotene	$i$. Nucleolus disappears
$B$. Zygotene	$ii$. Formation of recombination nodules
$C$. Pachytene	$iii$. Development of synapsis
$D$. Diplotene	$iv$. Chromosomes appear as thread-like structures
$E$. Diakinesis	$v$. Gene exchange occurs via chiasmata