What are the various stages of meiotic prophase-$I$? Enumerate the chromosomal events during each stage.

(N/A) $(i)$ Leptotene: This is the first phase of meiosis. During this phase,chromosomes become gradually visible. The compaction of chromosomes continues throughout Leptotene.
$\Rightarrow$ Each chromosome consists of two chromatids attached to a centromere,but they are tangled,so their dual nature is not clearly visible.
$(ii)$ Zygotene: During this stage,homologous chromosomes start pairing together,a process called synapsis. The complex formed by a pair of synapsed homologous chromosomes is called a bivalent or a tetrad.
$(iii)$ Pachytene: During this stage,bivalent chromosomes clearly appear as tetrads. This stage is characterized by the appearance of recombination nodules.
$\Rightarrow$ Crossing over occurs between non-sister chromatids of homologous chromosomes,which is an enzyme-mediated process involving the enzyme recombinase.
$\Rightarrow$ Crossing over leads to the recombination of genetic material between the two chromosomes.
$(iv)$ Diplotene: The beginning of diplotene is recognized by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other,except at the sites of crossing over.
$\Rightarrow$ These $X$-shaped structures are called chiasmata.
$(v)$ Diakinesis: This is the final stage of meiotic prophase-$I$. The chiasmata terminate,and the chromosomes are fully condensed. The nucleolus disappears,and the nuclear envelope breaks down.