Pre-embryo - human development, Biology

Pre-Embryo - Human Development

About thirty hours after fertilization the zygote goes through mitosis giving rise to 2 blastomeres. These blastomeres go through further cleavages and by the 3rd day after fertilization, the tiny mass of cells reaches the uterus. Through this time it is a solid ball of cells called morula. In the next three days the morula is changed into a hollow ball of cells called blastocyst. The cavity of blastocyst is filled along with fluid secreted by the cells. One portion of the blastocyst consists of a concentrated mass of cells that will give rise to the entire body of the new individual. This is termed as the inner cell mass (ICM). Interestingly, each cell of this mass has the capability to develop into a complete individual. Identical twins are formed if the ICM splits. The outer ring of cells of the blastocyst surrounding its cavity is termed as trophoblast and gives rise to all the extra-embryonic membranes including much more of the placenta. This stage of development is important as the cells begin to move for the first time and become rearranged to shape the new individual. This procedure you might recall is the beginning of morphogenesis. However the major morphogenetic events occur during the third to eighth week.

Posted Date: 2/1/2013 4:35:28 AM | Location : United States







Related Discussions:- Pre-embryo - human development, Assignment Help, Ask Question on Pre-embryo - human development, Get Answer, Expert's Help, Pre-embryo - human development Discussions

Write discussion on Pre-embryo - human development
Your posts are moderated
Related Questions
Q. What do you mean by Pericardial effusion? Collection of fluid in the pericardial sac is known as Pericardial effusion. All cases of pericarditis can lead to pericardial effu

Results of Mitral Valve Replacement: The risk of mitral valve replacement is reported as 3-5 per cent. It also depends on multiple factors like age, functional clas

Food Habits Food Habits: These must be known  so that the diets  can  be  recommended keeping in mind the  food preferences  of  the patient. Whether a person is  a vegetarian

Define about the Ionizing Radiation - carcinogenic? Ionizing Radiation: Electromagnetic (X-rays, gamma rays) and particulate (α - particles, β - particles, protons, neutrons) r

#question.what do u mean by parasitic habit.give account of various parasitic adoptation in animal.

Gibberellins - Plant Growth Substances In late 1920's Kurosawa observed that the medium in which the fungus Gibberella had grown could cause the abnormal tallness in rice seed

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain about chthalamus The realised niche of Chthalamus is reduced from its fundamental niche and it is limited to the upper tidal zone Lower  limits Out-competed

Q. Define Alcoholic Cardiomyopathy? In a case of dilated cardiomyopathy alcohol cardiomyopathy is suspected if there is history of alcohol intake of 100g/day for more than 10

What does ecological niche of an organism represent? Mention the scientific term used for modified form of reproduction in which seeds are produced without fusion of gametes.