Prophase   I  of  meiosis  is
   divided into five substages.
<LI> In  Leptonema  (Lepto:  thin), the replicated chromosomes begin to
condense at areas called chromomeres. Also, homologous chromosomes
begin to find each other in a process called homology search.
<LI> In  Zygonema  (Zygo:  pair), the chromosomes continue to condense,
and  homologous  chromosomes  undergo  loose  alignments with each
other,  forming bivalents, each of which contains four chromatids,
though the individual chromatid are yet visible at this substage.

   continue