Totipotency and pluripotency, Biology

Assignment Help:

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.


Related Discussions:- Totipotency and pluripotency

Patient after cardiac transplant, Patient after cardiac transplant ...

Patient after cardiac transplant The major focus of medical and nursing care after transplantation is to prevent early identification of rejection so that appropriate

Fiehes test and aniline chloride test, Q. Fiehes test and Aniline chloride ...

Q. Fiehes test and Aniline chloride test? Determine the adulteration in the given honey sample by Fiehe's test and Aniline chloride test This activity will help you to: •

What is crossing over, What is crossing over? In which period of meiosis do...

What is crossing over? In which period of meiosis does this event occur? Crossing over is the eventual exchange of chromosomal fragments among homologous chromosomes. The pheno

Define the functional properties of hydrocolloids, Define the functional pr...

Define the functional properties of hydrocolloids The hydrocolloids not only have the functional properties but also have nutritional characteristics. Most polysaccharide gums

Function of centrioles, FUNCTION In animal cells centrioles play import...

FUNCTION In animal cells centrioles play important role in initiation of cell division by arranging spindle fibres between two poles of cell.Thus they play a role in division o

Determine fragment of nucleic acid has a nucleotide sequence, If a fragment...

If a fragment of nucleic acid has a nucleotide sequence TAC can one assert that it is a codon or an anticodon? A nucleic acid having a TAC sequence surely is not tRNA, it is DN

Epidemiological association between hemophilia and hiv, Q. What is the epid...

Q. What is the epidemiological association between hemophilia and HIV infection? In the past the blood banks did not usually perform HIV detection tests and many hemophilic pat

Define about the nutritional deficiencies, Define about the nutritional def...

Define about the nutritional deficiencies? The nutritional deficiencies which have been identified in the group of elderly are of total calories, protein, vitamin A, vitamin C,

Explain lactate dehydrogenase, Lactate dehydrogenase (LDH) is one of the im...

Lactate dehydrogenase (LDH) is one of the important enzymes in glycolysis which catalyzes the interconversion of pyruvate and lactate as follows:   Functional lactate d

Permissive interaction - pancreas development, Permissive Interaction - Pan...

Permissive Interaction - Pancreas Development Figure describes the development of pancreas in a mammal. In an organism like mouse the pancreas is first seen as a diverticulum

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