Second stage of invagination, Biology

Assignment Help:

Second Stage of Invagination

The 2nd stage of invagination starts with release of secondary mesenchyme from the tip of archenteron into the blastocoel. The cells of secondary mesenchyme stay in which they are released at the tip of archenteron but their filopodia extend up to and attach to the inner side of the wall of blastocoel opposite to blastopore. Contractions of these ' filopodia pull the archenteron in the direction of the animal pole causing further invagination of the endoderm. Finally, the archenteron bends and its tip fuse along with the blastocoel wall on the ventral side where the mouth opens later. The secondary mesenchyme then disperses in the blastocoel and gives increment to mesodermal organs.


Related Discussions:- Second stage of invagination

How many germ layers originate the body of platyhelminthes, Q How many germ...

Q How many germ layers originate the body of platyhelminthes? In relation to this characteristic how are these animals classified? Platyhelminthes are the first triploblastic a

Difference between myosin and actin filaments, DIFFERENCE S BETWEEN MYOSIN...

DIFFERENCE S BETWEEN MYOSIN AND ACTIN FILAMENTS     Myosin filaments (primary filaments)   Actinfilament s (secondary filaments)

Carbon dioxide concentration in photosynthesis process, Q. Why is carbon di...

Q. Why is carbon dioxide concentration a limiting factor of the photosynthesis process? And When the carbon dioxide concentration is increased indefinitely is photosynthesis also i

Explain gametophyte, "In these autotrophs, sporophyte is the dominant gener...

"In these autotrophs, sporophyte is the dominant generation. Gametophyte is also photosynthetic and not dependent on sporophyte for nutrition."  These autotrophs are:  a.  P

Absorption of proteins in infants, Absorption of proteins in infants In...

Absorption of proteins in infants In  infants, permeability of  the  intestine appears to be greater than  in  later  life, and some  large  protein molecules such as antibodie

Explain glycolysis, Explain glycolysis? Name the two monosaccharides w...

Explain glycolysis? Name the two monosaccharides which readily enter the glycolytic pathway. Illustrate a diagrammatic sketch of the microscopic view of a mammalian sperm a

Determine the excitation threshold concerning neurons, How different are th...

How different are the concepts of action potential, resting potential and excitation threshold concerning neurons? Action potential is the maximum positive voltage level achiev

Describe genetic recombination , Describe Genetic Recombination ? Genet...

Describe Genetic Recombination ? Genetic recombination, which provides the variation necessary for evolution, can occur through a variety of processes during cell reproduction:

Aschelminthes, General characters of aschelminthes

General characters of aschelminthes

What is trophic levels and food webs, What is Trophic Levels and Food Webs?...

What is Trophic Levels and Food Webs? Trophic Levels and Food Webs : Energy flows and nutrients are cycled through an ecosystem via organisms that feed on one another. When c

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