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 dietary constituents affecting the calcium absorption, How dietary cons...

How dietary constituents affecting the calcium absorption? Several dietary constituents have an effect on calcium absorption. The differences in fractional absorption from diff

Explain the kingdom fungi organisms, Explain the Kingdom Fungi organisms? ...

Explain the Kingdom Fungi organisms? Kingdom Fungi consists of mostly eukaryotic, multicellular, non-photosynthetic organisms that derive their nutrients by absorption. Fungi

Aortic valve replacement-types of surgery in ar, Aortic Valve Repla...

Aortic Valve Replacement :  Technique: Surgical technique is not much different from what has already been described for aortic stenosis. Care must be taken to avoid VF

Nutritional management goals for atherosclerosis, Q. Nutritional Management...

Q. Nutritional Management Goals for atherosclerosis? The nutritional management goals include: • Reduction of weight if overweight or obese • Reduction in the intake of

How the average number of offspring raised to adulthood, Researchers (Helle...

Researchers (Helle et al., 2004) analyzed rates of twin births in the Sami population of Northern Scandinavia during the eighteenth and nineteenth centuries. They found that (1) a

Explain prophylaxis - sexually transmitted infections, Prophylaxis Many...

Prophylaxis Many experts recommend that sexually assaulted adults and adolescents be given treatment to prevent sexually transmitted infections, including therapy for gonorrhea

Determine the term - techniques visualise anatomy, Determine the term - tec...

Determine the term - techniques visualise anatomy Some techniques visualise anatomy, provide objective confirmation of structural abnormality. These include neuroradiological i

What is catalyzes a substrate level phosphorylation, The enzyme in the TCA ...

The enzyme in the TCA cycle that catalyzes a substrate level phosphorylation is -citrate dehydrogenase -succinate thiokinase -isocitrate dehydrogenase

Show the characteristic of the dna molecule, Q. One characteristic of the D...

Q. One characteristic of the DNA molecule is its replication capability. What are the consequences of failures during the DNA replication? Ideally the DNA molecule should replicate

Streptococcal antibody test, In about 80 per cent of ARF patients, ASO titr...

In about 80 per cent of ARF patients, ASO titre is significantly raised. ASO titres vary with age, geographical area and other fevers, which influence frequency of streptococcal in

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