Totipotency and pluripotency, Biology

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.

Posted Date: 1/28/2013 8:12:15 AM | Location : United States







Related Discussions:- Totipotency and pluripotency, Assignment Help, Ask Question on Totipotency and pluripotency, Get Answer, Expert's Help, Totipotency and pluripotency Discussions

Write discussion on Totipotency and pluripotency
Your posts are moderated
Related Questions
Water Stress - Responses of Plants to Stress Water stress in a plant can result from drought, excess salinity in the soil and very low or high temperatures. It has been found

Q. What are pioneer species? What is the role of the pioneer species? The Pioneer species are those first species that colonize places where previously there were no living bei

Why can the allantois be considered an adaptation to terrestrial life? The allantois is an adaptation to dry land because in embryos of oviparous terrestrial beings, like repti

How can the concept of recombination frequency be used in genetic mapping? Genetic mapping is the determination of the location of the genes in a chromosome. By determining

It is a clinical syndrome wherein heart fails to pump blood at a rate required by the tissues of the body or it can do so only with an elevated filling pressure. This may be due to

Define Recommended Dietary Allowances for Vitamin D? The recommendations of vitamin D are expressed as IU. 1 IU is defined as the activity contained in 0.025 mcg of cholecalci

How is the structure of a mitochondrion well adapted for the activities it carries out? The mitochondrial membranes segregate the enzymes and reactants of the Krebs cycle, faci

Neonatal  hypoglycaemia Hypoglycaemia is a metabolic condition of newborn piglets that develops in first few days of life due to decreased caloric intake and increased cataboli

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Gregor Mendel's Law of Independent Segregation referred to which of the following genetic elements? A. Alleles of two genes that reside on the similar chromosome B. Alleles