Chromosomes
At leptotene stage of meiotic prophase, chromosomes appear as beaded structures, bead-like nodules being known as chromomeres. Size of chromomeres and interchromomeric regions are not constant, so that every leptotene has its own particular pattern. The DNA is though known to concentrate in the chromomeres, but is believed to be present in the inter-chfomomeric regions also. A diploid nucleus has two chromosomes of each type. Two similar chromosomes, are known as homologous chromosomes, which come in contact at zygotene and pair lengthwise throughout their length.