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| 1. |
E. With the help of suitable diagrams.explain the five stages of prophase-1of meiosis |
| Answer» PLEASE search for the DIAGRAM in google as you'll get a better diagram in detailPROPHASE I is the longest phase of meiosis-1 this includes 5 sub stages:LEPTOTENEAll the chromosomes cluster together towards centrioles and appear like a BOUQUET chromosomes become visible as LONG and THICKIn ANIMAL cell this cluster is called as BOUQUETIn PLANT cel this cluster is called SYNIZESIS ZYGOTENEPairing of chromosome occur between HOMOLOGUS chromosome only pairing of homologus chromosomes take place and this process is called SYNAPSISpaired homologus chromosomes are also called as BILATERAL or TETRAD pairing is mediated by a NUCLEOPROTEIN COMPLEX called as SYNAPTONEMAL COMPLEXPACHYTENECrossing over on recombination occur between NON SISTER CHROMATIDS of HOMOLOGUS CHROMOSOMESBivalents or Tetrads are clearly visibleCrossing over is mediated by an enzymes called RECOMBINASE which activity binds at recombinase nodule to complete the process of crossing over DIPLOTENELONGEST PHASE At the point of cross over a X shaped sturture is formed called as CHIASMATADissolution of synaptonemal complex take place and it lead to seperation of chromosome at all the points except at the point of cross over DIAKINESISSpindle and ASTER are formed Centrioles move to opposite polesTerminalisation of chiasmata take place which lead to the seperation of chromatids Disappearance of nuclear memebrane and nucleolusI HOPE THIS WAS HELPFUL | |