Bio Room

Cleavage in human embryo: After the fertilization process is done the resulting zygote undergoes rapid and  repeated mitotic division which result in the formation of bunch of small cells . This process in known as cleavage .  Cleavage is different from normal cell division in which the cells become smaller and smaller but the total volume of the embryo remains constant.  Cleavage of the zygote occurs in the fallopian tube of the uterus.  It takes 30 hours to complete the first cleavage which divides  the single celled zygote longitudinally in to two blastomeres of un equal size and then followed by another division after 10 hour from the 1st cleavage in right angle to the plane of 1st cleavage resulting in to four blastomeres . During early cleavage the embryo slowly moves towards uterus.  Morula stage-   In fourth day the embryo reaches the uterus during this the embryo reches 16- 32 called stage called morula ,  This is the solid mass of cell ...