Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Totipotency and Pluripotency
In the starting we said that the fertilized egg cell (zygote) has the capacity or potentiality to give rise to all kinds of cell types, like a blood cell or a bone cell or a muscle cell etc. In embryological terminology such a cell is said to be totipotent. The zygote cleaves and makes a large number of blastomeres. The blastomeres may as well remain totipotent up to a certain stage and have the capacity to form every cell type of the organism. Though, as development proceeds the various blastomeres lose totipotency but may still be pluripotent. By pluripotent it is meant that they are able to make several but not all of the various cell types or tissues. Ultimately, with further development, even the pluripotency is lost and different groups of cells of the embryo are now capable of forming only one particular cell type or tissue.
For instance, up to a certain stage of embryonic development prospective ectodermal cells can make either epidermis or neural tissue, i.e. they are pluripotent. But at a later stage cells of one region of ectoderm can make only epidermal tissue and those of another region can distinguish only into neural tissue. What may be the cause of progressive restriction of potency in diverse embryonic cells although they are all descendents of the same single cell, zygote? Each one of these embryonic cells contains a nucleus which is also the descendent of similar zygotic nucleus. Does the restriction in potency in several embryonic cells result from differential distribution of specific cytoplasmic substances between different blastomeres during cleavage of zygote and subsequent divisions? We may ask a identical question with regards to the nucleus which contains the genes that direct the differentiation into specific tissues and cells types.
CELL COAT (GLYCOCALYX) Present in Protists and animal cells. Usually made of oligosaccharide side chains of glycolipids and glycoproteins. Cell coat has very charged t
Q. What are the differentiations of the cell membrane? In some kind of cells, the cell membrane presents differentiations that are necessary for the specific functions of the c
Explain solid salt and saturated aqueous solution? In this example, the equilibrium system consists of crystalline PbCl 2 and an aqueous phase containing the species H 2 O, P
Q. What do you mean by Canning? Canning The term canning is generally applied to foods, more specifically, to the foods preserved by heat processing. It aimgto destroy microo
introduction in fungai
canal system in porifera
Explain Protein hydrolysates It is valued for their superior nutritional qualities, including increased bioavailability and reduced antigenecity. Several enzymatic modification
Echinococcosis (hydatidosis) Echinococcosis, also called hydatidosis, is a global problem particularly in countries where sheep and cattle raising forms the major animal husba
Q. What is the parasite that causes giardiasis? How is it transmitted and what are the typical manifestations of the disease? The Giardiasis is a protozoal infection caused by
Illustrate the Respiratory System In general, respiration and breathing are understood to be same. But it is not so. Breathing simply means taking in oxygen from air and giving
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd