Meroblastic or partial cleavage, Biology

Assignment Help:

Meroblastic or partial cleavage

The egg does not divide totally because divisions are restricted to only a part of the egg where as the rest of the egg remains completely uncleaved. It is of two types:

A. Discoidal meroblastic cleavage: It occurs in the heavily yoked macrolecithal and highly telolecithal eggs, as for instance in cephalopod molluscs, reptiles, birds and monotremes (egg laying mammals). The cleavage is restricted to the cytoplasmic germinal disc located at the animal pole. Even the germinal disc divides incompletely where as the entire yolk mass remains undivided.

B. Superficial meroblastic cleavage: This takes place in the centrolecithal eggs of insects. Cell divisions are restricted to the peripheral cytoplasmic layer whereas the centrally located yolky is left undivided.


Related Discussions:- Meroblastic or partial cleavage

Illustrate the maturation of honey, Q. Illustrate the maturation of honey? ...

Q. Illustrate the maturation of honey? Honey is the oldest sweet food known to man. Although honey is a natural sweetener, it is considered a refined sugar because 96% of dr

Metabolism of fructose, Fructose is an abundant sugar in the human diet; su...

Fructose is an abundant sugar in the human diet; sucrose (table sugar) is a disaccharide that when hydrolyzed yields glucose and fructose and fructose is also a major sugar in hone

Explain how the boll weevil populations changed, The boll weevil, an insect...

The boll weevil, an insect native to Mexico and Central America, is another pest of commercial cotton. When chemical insecticides were first discovered, they proved highly effectiv

What is the estimated percentage of water in the human body, Q. What is the...

Q. What is the estimated percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual? Approximately 65% of t

Specie concept, what is nomenalistic specie concept

what is nomenalistic specie concept

Genomic dna libraries , A genomic DNA library is made from the genomic DNA ...

A genomic DNA library is made from the genomic DNA of an organism. For instance, a mouse genomic library could be made by digesting mouse nuclear DNA with a restriction nuclease to

Volvox Colonial Existence, Necessity of interdependence of Volvox organisms...

Necessity of interdependence of Volvox organisms in the colonial existence

Some precautionary measures to avoid addiction, SOME PRECAUTIONARY MEASURES...

SOME PRECAUTIONARY MEASURES TO AVOID ADDICTION - DEADDICTIO N - First phase of treatment is detoxification. Next phase is of psychotherapy and counselling. Deadi

Primitive nervous system - nerve net, Primitive Nervous System - Nerve Net ...

Primitive Nervous System - Nerve Net A nervous system creates its appearance for the first time in the phylogeny among Cnidaria. In this group the nerve cells make an irregula

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