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

Dietary fats required for dyslipidemia, Q. Dietary Fats required for dyslip...

Q. Dietary Fats required for dyslipidemia? Dietary Fats: There is a consistent support for the hypothesis that both the quantity and quality of fat are directly associated with

Define fuel molecules and lipogenesis, Define Fuel Molecules and Lipogenesi...

Define Fuel Molecules and Lipogenesis? Lipogenesis is a collective name for the complex process of producing lipids (fatty acids) from smaller precursor molecules. The synthesi

Help, about how humans survive and reproduce currently. In your journal, wr...

about how humans survive and reproduce currently. In your journal, write down three adaptations that help humans have differential survivability, and three adaptations that help hu

Define the normal squid intracellular saline, At 1 AM, a researcher places ...

At 1 AM, a researcher places a healthy squid giant axon in a bath of normal squid physiological extracellular saline and internally perfuses the axon with normal squid intracellula

Endocine organ, #question.endocrine organ in crustaceans

#question.endocrine organ in crustaceans

Endoplasmic reticulum, ENDOPLASMIC RETICULUM It is also known as Endosk...

ENDOPLASMIC RETICULUM It is also known as Endoskeleton of the cell, Endomembranous system of the cell. Garnier (1897) first observed them and called Ergastoplasm. E.R.

Explain about the incidence of defects in color vision, Explain about the I...

Explain about the Incidence of defects in color vision Defects in colour vision can either be congenital or acquired. Males are more affected than females. Out of the populatio

Define denaturation, Denaturation: With respect to the nucleic acids, refe...

Denaturation: With respect to the nucleic acids, refers to the conversion from the double-stranded to single-stranded state, many times achieved by heating or alkaline conditions.

What are primary mediators, Primary mediators are those, which are produced...

Primary mediators are those, which are produced before degranulation. These primary mediators are stored in granules. Some of the primary mediators are histamine, heparin, protease

Why mosquito bites and it causes itching, Why mosquito bites and it causes ...

Why mosquito bites and it causes itching? A mosquito does not really bite you, of course. It sucks your blood. To help enable effective blood sucking, it firstly injects ant

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