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

Ruminal tympany (bloat), R uminal tympany (Bloat) It is the over-diste...

R uminal tympany (Bloat) It is the over-distension of the rumen with gases which may be either frothy or free gas. The disease is characterized by change in silhouette of the

Parasitology, how trematodes/nematodes adapt to their parasitic mode of fee...

how trematodes/nematodes adapt to their parasitic mode of feeding

Vertebrata, VERTEBR A T A It is divided into two parts -        1. ...

VERTEBR A T A It is divided into two parts -        1. Agnetha                    2. Gnetha S.No. C haracter A gnetha G

Explain caspofungin, Explain Caspofungin It is available only for intra...

Explain Caspofungin It is available only for intravenous administration and is FDA-approved for treatment of esophageal candidiasis, candidemia, and intra-abdominal abscesses,

Define nutrient needs and recommended dietary intake, Define Nutrient Needs...

Define Nutrient Needs and Recommended Dietary Intake? Table depicts growth of normal well-to-do Indian children. Their intake is the criteria to assess nutrient requirements t

Define nutritional requirements for extreme environments, Define Nutritiona...

Define Nutritional Requirements for Extreme Environments? Human beings have been able to survive and work under extreme environments of almost all regions of the earth, from po

State about osteogenesis, State about osteogenesis Embryologically, ost...

State about osteogenesis Embryologically, osteogenesis may be classified as either intramembranous or endochondral. When the ossification occurs directly, it is defined as intr

Fertilization in earthworm, In earthworms, when the ovaries mature, the cli...

In earthworms, when the ovaries mature, the clitellum secretes a viscous substance in the form of a girdle. This girdle hardens in to a cocoon around the clitellum. The ova are dis

Define rhizoids - types of hyphae, Define Rhizoids - Types of Hyphae? ...

Define Rhizoids - Types of Hyphae? Rhizoids - These are brown slender root like structures which arise in cluster from each node of the stolon. These penetrate the substratum

Skeletal tissue, what is the classification of skeletal tissue?

what is the classification of skeletal tissue?

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