Epiboly of ectoderm, Biology

Assignment Help:

Epiboly of Ectoderm

Like the presumptive endodermal notochordal and mesodermal cells migrate inward the areas in the epiblast vacated through them are occupied by expansion (epiboly) of the embryonic epidermal and neural ectoderm. At the same time with gastrulation the ectodermal cells expand as a sheet beneath the vitelline membrane outward from the area opaca finally encircling the yolk. The upper surfaces of ectodermal cells of area opaca are in from contact with the inner surface of vitelline membrane and they spread along this inner surface of the membrane. Also, these cells extend pseudopodia processes which attach to inner side of the vitelline membrane. It appears that these marginal cells of area opaca migrate outward along the inner surface of the vitelline membrane with the help of these pseudopodia and at the same time drag along the expanding sheet of ectodermal cells of that they are the leading members. Removal of the vitelline membrane inhibits epibolic movements and expansion of ectoderm.


Related Discussions:- Epiboly of ectoderm

Explain about the biofertilizers, Explain about the Biofertilizers Biof...

Explain about the Biofertilizers Biofertilizers, are the cultures of microorganisms used for inoculating seed or soil or both under ideal conditions to increase the availabilit

Ganong''s potometer, What happens to the movement of the air bubble if the ...

What happens to the movement of the air bubble if the apparatus is kept in i. In the dark ii. In sunlight iii.In front of a fan

What is muller manoeuver explain in details, What is Muller Manoeuver expla...

What is Muller Manoeuver explain in details? In this manoeuver, patient forcibly inspires while the nose is held closed and mouth firmly sealed for 10 seconds. It exaggerates t

Explain about bimodal diurnal pattern, Explain about bimodal diurnal patter...

Explain about bimodal diurnal pattern Animals that show a bimodal diurnal pattern have their activity controlled by two biological clocks -  one that controls the time of onset

What is rh typing of mother & fetus hemolythemolytic disease, What is the R...

What is the Rh typing of the mother and of the fetus in the hemolytic disease of the newborn? In a hemolytic disease of the newborn the mother is Rh- and the fetus Rh+. In thes

Aortic valve replacement-surgical techniques, Aortic Valve replacement ...

Aortic Valve replacement :  The initial steps of the operation have been described earlier. Ascending aorta is cannulated. A single two-stage atrio-venous cannula is inse

Nursing responsibilities while administering immunization, NURSING RESPONSI...

NURSING RESPONSIBILITIES WHILE ADMINISTERING IMMUNIZATION Use one sterile syringe and needle for each injection.  Use only the diluent supplied along with measles and

What is the law of limiting factors, What is the law of limiting factors? H...

What is the law of limiting factors? How would the rate of photosynthesis be affected if the soil water becomes limiting? Describe.

Nuclease, Nuclease  is an enzyme which degrades the nucleic acids. A nuclea...

Nuclease  is an enzyme which degrades the nucleic acids. A nuclease can be DNA-specific (a DNase), RNA-specific (RNase) or non-specific. It might act only on single stranded nuclei

Nucleolus, NUCLEOLUS Discovered by Fontana and name given by Bowm...

NUCLEOLUS Discovered by Fontana and name given by Bowman. It is naked structure that is attached to chromatin at specific point called nucleolar organiser region or

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd