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

Promotion - stages of carcinogenesis, Promotion - Stages of carcinogenesis ...

Promotion - Stages of carcinogenesis The second stage or promotion is reversible and does not include changes in structure of DNA but rather in the expression of the genome of

Determine the case when starches treated with heat, Determine the case when...

Determine the case when starches treated with heat In the case of starches treated with heat in presence of acid or alkali, the alteration is a minor fragmentation; similarly,

.phylum pisces, wt is an air bladder and its function wt is catadromous and...

wt is an air bladder and its function wt is catadromous and anadromus migration

Triple vessel disease , Triple Vessel Disease (TVD) :  Patients with tripl...

Triple Vessel Disease (TVD) :  Patients with triple vessel disease and impaired left ventricular function do badly on medical treatment. They are candidates for CABG. Operation is

Bergmann's method of cell plating, Bergmann's Method of Cell Plating I...

Bergmann's Method of Cell Plating In this method free cells are suspended in a liquid medium at a density twice the finally desired plating density. Melted agar containing med

Define need of vitamin e and k during pregnancy period, Define need of vita...

Define need of vitamin E and K during pregnancy period? Vitamin E needs are believed to increase during pregnancy but deficiency in humans rarely occurs. Vitamin E in the infan

Identify the enzymes utilization in cheese production, Cheese Production ...

Cheese Production Cheese production involves the conversion of the milk protein, k-casein to paracasein by a defined, limited hydrolysis, catalysed by chymosin (rennin). In the

Proteins, what is he importance of proteins for living beings

what is he importance of proteins for living beings

Define role of vitamin k in controlling gene expression, Define role of Vit...

Define role of Vitamin K in controlling gene expression? Prithrombin, a protein required for blood clotting is assembled with a large number of glutamic acid residues. In the p

Zoology, find the habits and habitats of scyphas?

find the habits and habitats of scyphas?

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