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

Important causes of degradation of ecosystem, Important Causes of Degradati...

Important Causes of Degradation of Ecosystem The important causes that have lead to the degradation of the ecosystem. Deforestation Overgrazing Agriculture

Two main pollutants that contribute to acid rain, (a) What are the two main...

(a) What are the two main pollutants that contribute to acid rain? (b) Where do these pollutants come from? (c) What direct or indirect effect is 'acid rain

What are the two major morphological patterns of cnidarians, Q. What are th...

Q. What are the two major morphological patterns of cnidarians? Concerning locomotion how do these forms differentiate from each other? Morphologically, cnidarians classify as

Injection route - administration of drugs, Injection Route An injecti...

Injection Route An injection is an unpleasant experience for a person at any age and is particularly traumatic to the small child who often lives in fear to the next "need

Spina bifida cystica, Spina Bifida Cystica There is a protrusion of me...

Spina Bifida Cystica There is a protrusion of meninges and spinal cord a) Meningocele- it is relatively uncommon lesion (4-5 per cent). In this there is protrusion of me

Explain about the drying - methods of food processing, Explain about the Dr...

Explain about the Drying - methods of food processing? Drying is the oldest and probably the simplest way of preserving food. It is usually accomplished by the removal of water

Epithelial tissues., function , structure and lo of location of germinal e...

function , structure and lo of location of germinal epithelium

Explain the factors affecting gi of foods, Explain the Factors Affecting GI...

Explain the Factors Affecting GI of Foods? A variety of factors affect GI of foods. The factors which affect the rate of glucose absorption from starchy foods and therefore the

Implant surface affect osseointegration, Implant surface affect Osseointegr...

Implant surface affect Osseointegration Surface topography is critical as rough surfaces produce better bone fixation as compared with smooth surfaces, and osteoblast like cell

Role of glucocorticoids in controlling gene expression, Define Role of Gluc...

Define Role of Glucocorticoids in controlling gene expression? Glucocorticoids are another class of hormones involved in the regulation of lipogenic enzymes, but their role in

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