Exchange of chromosome segments between maternal and paternal chromatids during meiosis is called

At which phase of meiosis,bivalent chromosomes align on the equatorial plate $:-$

Match the following stages of Prophase-$I$ of meiosis with their respective characteristics:

$I$. Leptotene	$A$. Chromosomes appear as clear bivalents/tetrads
$II$. Zygotene	$B$. Chromosomes appear like a thread (beaded appearance)
$III$. Pachytene	$C$. Chromosome condensation reaches its maximum
$IV$. Diakinesis	$D$. Synapsis of homologous chromosomes occurs

During the first metaphase of meiosis,the centromeres:

Lampbrush chromosomes are visible in:

$S$ - Statement: Meiosis occurs during the formation of reproductive cells. $R$ - Reason: During meiosis,the genetic material replicates twice,and the cell divides twice.