Bio Room

Implantation: The attachment of the blastocyst to the uterine wall is known as Implantation . This process starts 5- 6 days after fertilization. The inner cell mass of blastocyst in placed against endometrium ,the inner most layer of uterus.  The trophoblastic cell break the endometrium at the point of contact and the blastocyst sinks into a pit formed in endometrium.  Finger like projections (villi) are formed in the contact point in order to supply nutrients from mother to the developing embryo through placenta .  Chorion is also developed from tropoblast cells ,which secret human chorionic gonadotropin (HCG) hermone which maintains and stimulates the corpous leuteum to secrete progesterone hermone which prepares the endometrial wall for implantation and growth of the developing embryo.  Function of placenta- Placenta is like a lifeline for the developing one which helps in various way to sustain life in the womb. 1. The oxygen and required nutrients are transm...

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 ...

  What is fertilization? Fertilization is the process by which the fusion of  haploid male gamete ( sperm) and haploid female gamete (ovum) takes place and formation of diploid zygote formed. It may be external ( in frog )or internal . Fertilization takesplace in ampula of fallopian tube of human being. Process of fertilization: During copulation male discharges semen in to the vagina of the female. Nearly 300 million sperm are released with semen. From vagina the sperms are moved towards the ampula of fallopian tube partly by the spiral movement of the tail of sperm and partly by the help of muscles contraction of uterus. Here in the fallopian tube the sperm lives only 3 to 4 days. It took 12 to 24 hours for sperm to fertilize an egg.  From this the process of fertilization takesplace in various stages.  1.What is capacitation?? In order to fertilize an egg the sperm acquire some capacity in fallopian tube which increases the motility of the sperm capable to underg...