At what stage of development is the embryo called marula
Answers
Answered by
11
It is included in the embryo formation in Human beings:
Morula formation is happening soon after the fertilization stage has been complete and the ova or ovum has been completely fertilized. The zygote begins the cleavage or segmentation to go further into the processes. Cleavage consists of early Mitotic division of a fully fertilized egg without involving in the actual growth of daughter cells. There is rapid synthesis of a newly formed DNA and increased oxygen consumption (exhaustion of females are particularly noticed in this stage). The surface to volume ratio and nucleo to cytoplasmic ratio increase in a great rate. The cells which have been formed in this stage after the cleavage has occurred is called blastomeres.
Cleavage is a simple and holoblastic (when division of the whole cell recur) in human beings as there is little yolk present in it. The first cleavage is along animal-vegetal axis or referred to primary axis. It is where, the process begins to slow down and is completed within the next 30 hours of fertilization. One of the two blastomeres is, however, slightly larger than the next one. Hence, the first cleavage is holoblastic and slightly unequal (in the divisional phase).
Second cleavage is at the right angles to the first one, it takes about 20-30 hours and is completed slightly earlier in the larger blastomere so that it is a transitional 3-celled stage which is going to appear. Subsequent divisions are clearly rapid in it (third blastomere taking mere 12 hours to complete) and occur in three different sub-divided planes.
They produce a solid ball, structure wise, of many blastomere cells (including the three blastomeres itself) called morula. Phase of compaction ensues into an 8-celled stage of cells. Morula has almost the same size of that in a fertilized egg due to the presence of a thin layer called zone pellucida which is a middle glycoprotein.
Morula has a total of 16-32 cells. The cells are compacted and of two types, outer slightly smaller peripheral cells with some tight junctions around it than the inner mass of cells with some gap junctions. During the cleavage phase the young embryo descends into the Fallopian tube slowly due to feeble fluid produced by a special epithelial secretion and cilia. Ultimately, it reaches the uterus taking about 4-6 days to complete the cycle. Corona radiata subsequently, dissolves away during this period.
Morula formation is happening soon after the fertilization stage has been complete and the ova or ovum has been completely fertilized. The zygote begins the cleavage or segmentation to go further into the processes. Cleavage consists of early Mitotic division of a fully fertilized egg without involving in the actual growth of daughter cells. There is rapid synthesis of a newly formed DNA and increased oxygen consumption (exhaustion of females are particularly noticed in this stage). The surface to volume ratio and nucleo to cytoplasmic ratio increase in a great rate. The cells which have been formed in this stage after the cleavage has occurred is called blastomeres.
Cleavage is a simple and holoblastic (when division of the whole cell recur) in human beings as there is little yolk present in it. The first cleavage is along animal-vegetal axis or referred to primary axis. It is where, the process begins to slow down and is completed within the next 30 hours of fertilization. One of the two blastomeres is, however, slightly larger than the next one. Hence, the first cleavage is holoblastic and slightly unequal (in the divisional phase).
Second cleavage is at the right angles to the first one, it takes about 20-30 hours and is completed slightly earlier in the larger blastomere so that it is a transitional 3-celled stage which is going to appear. Subsequent divisions are clearly rapid in it (third blastomere taking mere 12 hours to complete) and occur in three different sub-divided planes.
They produce a solid ball, structure wise, of many blastomere cells (including the three blastomeres itself) called morula. Phase of compaction ensues into an 8-celled stage of cells. Morula has almost the same size of that in a fertilized egg due to the presence of a thin layer called zone pellucida which is a middle glycoprotein.
Morula has a total of 16-32 cells. The cells are compacted and of two types, outer slightly smaller peripheral cells with some tight junctions around it than the inner mass of cells with some gap junctions. During the cleavage phase the young embryo descends into the Fallopian tube slowly due to feeble fluid produced by a special epithelial secretion and cilia. Ultimately, it reaches the uterus taking about 4-6 days to complete the cycle. Corona radiata subsequently, dissolves away during this period.
Similar questions