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

How did pasteur experiment vary from spallanzani, How did Pasteur's experim...

How did Pasteur's experiment vary from Spallanzani's experiment? Instead of sealing the flask in the experimental group after boiling, Pasteur used a flask with a curved neck,

Explain ground meristem in primary root growth, Explain Ground Meristem in ...

Explain Ground Meristem in Primary Root Growth? To review, the protoderm is the primary tissue that eventually forms the outside layer that covers the root and shoot and leaves

What happens to the tsh blood level in hypothyroidism, What happens to the ...

What happens to the TSH (thyroid-stimulating hormone) blood level in hypothyroidism? Why is there enlargement of the thyroid in the endemic goiter disease? When there is low T3

Factor influencing lipid oxidation - temperature, Factors affecting lipid o...

Factors affecting lipid oxidation Temperature In general, the rate of oxidation increases as the temperature is increased. Temperature also influences the relation betw

Illustrate numerical taxonomy, Q. Illustrate Numerical Taxonomy? Taxono...

Q. Illustrate Numerical Taxonomy? Taxonomy today is, in many dctails, different from what it was a generation ago. The use of computers by taxonomists has established an intere

Nutition in animals, describe each and every step in nutrition in animals?

describe each and every step in nutrition in animals?

Sterility in angiosperms, Sterility in Angiosperms Sterility in angios...

Sterility in Angiosperms Sterility in angiosperms may arise due to several causes. Either the anther may not be formed, or anthers are formed but meiosis may be abnormal. A

Neurochemistry of attention, Neurochemistry of Attention Different neur...

Neurochemistry of Attention Different neurotransmitters systems are implicated in attention. Cholinergic, dopaminergic and serotonergic systems play major roles in neurochemica

Direct approach to counseling, Q. Direct Approach to counseling? The di...

Q. Direct Approach to counseling? The direct approach to counselling is also called as the problem-solving approach. The counsellor collects relevant information which aims to

What is chylomicrons , Chylomicrons, the widest of the lipoproteins, are...

Chylomicrons, the widest of the lipoproteins, are synthesized in the intestine. They including ingested triacylglycerols to other tissues, mainly skeletal muscle and adipose tissue

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