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

Explain about dry heat sterilization, Q. Explain about Dry heat sterilizati...

Q. Explain about Dry heat sterilization? It is used to sterilize glass ware, forceps, scissors, scalpels, all glass syringes, swabs, some pharmaceuticals products such as liqui

Describe about postural changes in dynamic auscultation, Describe about Pos...

Describe about Postural Changes in Dynamic Auscultation? a) On sudden assumption of supine position from standing on sitting position or sudden passive elevation of both legs:

Crustaceans - hormones in growth and reproduction, Crustaceans - Hormones i...

Crustaceans - Hormones in Growth and Reproduction Arthropods have a tough and frequently hard exoskeleton made up of cuticle composed of chitin and protein. The cuticle impose

Define briefly about the seed proteins, Define briefly about the Seed Prote...

Define briefly about the Seed Proteins? Although a large number of plants produce seeds having protein contents in excess of 15%, only a few are utilized for food, eg. soybean,

In hormonal terms why does menses occur, Q. In hormonal terms why does mens...

Q. In hormonal terms why does menses occur? Menses is the endometrial monthly desquamation that occurs as the progesterone and estrogen levels fall after the regression of the

Residual soils-types of soil, Residual Soils Residual soils are formed ...

Residual Soils Residual soils are formed at the same site where the weathering of the parent rock has taken place or soils formed in situ from the underlying rocks. These are a

Disinfectant, General information about disinfectants A disinfectant is...

General information about disinfectants A disinfectant is a chemical that kills disease-causing agents on contact. Natural disinfection agents, such as sunlight, heat, keeping

Evolutionary implications of natural regulation, Evolutionary Implications ...

Evolutionary Implications of Natural Regulation Many changes in abundance can be attributed to changes in extrinsic factors such as weather, disease or predation. But some cha

Why do sharks need to agitate their body to swim, How dissimilar are the sw...

How dissimilar are the swimming strategies in osteichthyes and in chondrichthyes? Why do sharks need to agitate their body to swim while bony fishes do not? Bony fishes have a

Which term describes first step in production of urine, In studies of human...

In studies of human body, which of the below terms is used to describe the first step in production of urine? Is it: a) Tubular reabsorption b) Tubular secretion c) Glome

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