Question

what are the characteristics of silent features of 5 families with examples

Answer 1

 Lampbrush chromosomes  are the special types of chromosomes found in the growing oocytes (immature eggs) of most animals, except mammals . They were first observed by Flemming in 1882. These chromosomes characteristically show lampbrush form ( bottle brushes) during the  extended diplotene stage of meiotic prophase I. At this stage, they  consist of an axis from which paired loops (consist of transcriptionally active DNA) extend in opposite directions, giving the appearance like a bottle brush.  At this stage, they are actually bivalents consisting of two synapsed homologous chromosomes. Each of homologous chromosomes consists of two sister chromatids which further are differentiated into transcriptionally active and inactive regions. Transcriptionally active region  present in loops synthesize large amount of mRNA, necessary for the synthesis of yolk.
 
Synaptonemal complex is a complex formed by synapsed homologous chromosomes. It is a zipper like protein complex that act as scaffold for interacting  chromatids to complete their crossover activities. The non sister chromatids of homologous chromosomes start to pair together by a process called synapsis during the zygotene stage of prophase I of meiosis I.  So, the formation of synaptonemal complex also occur duringthe zygotene stage of prophase I of meiosis I.