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

Parts, How many parts of human body?

How many parts of human body?

In which phase of the cell cycle does the dna duplicate, Q How are the conc...

Q How are the concepts of chromosome, chromatids and chromatin related? In which phase of the cell cycle does the DNA duplicate? Chromatin is a set of filamentous the DNA molec

Can you explain right ventricle enlargement, Q. Can you explain Right Ventr...

Q. Can you explain Right Ventricle Enlargement? The right ventricle (RV) is roughly triangular in shape on the PA view, with a near vertical base - apex axis. When this chamber

How do antibodies work to neutralize antigens, Q. How do antibodies work to...

Q. How do antibodies work to neutralize antigens? The immunoglobulins or antibodies act to facilitate the destruction of antigens: they attract phagocytic leukocytes, they dire

Why could a disease be more serious in a population, Why could a disease be...

Why could a disease be more serious in a population with a low genetic diversity? A population with a low genetic diversity could be more expected to be wiped out by a disease

Classification of hypertension, Q. Show basic Classification of hypertensio...

Q. Show basic Classification of hypertension? Unlike many other diseases, hypertension develops insidiously (without symptoms). In 90% of hypertension cases, the cause is unkn

Why is rubella during gestation a threat to the fetus, Why is rubella durin...

Why is rubella during gestation a threat to the fetus? If occurring during gestation rubella is a dangerous disease due to the virus crosses the placenta and contaminates the f

Pyramid of energy - ecological pyramids, Pyramid of Energy - Ecological Pyr...

Pyramid of Energy - Ecological Pyramids When we wish to compare the functional roles of the trophic levels in an ecosystem, an energy pyramid is probably the most informative.

Explain epidemiological studies, Epidemiological studies The use of ava...

Epidemiological studies The use of available data from  the positive epidemiological studies in  the  risk assessment is encouraged. Data derived fiom human clinical studies, s

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