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

Does the fish heart pump venous or arterial blood, Does the fish heart pump...

Does the fish heart pump venous or arterial blood? The venous blood coming from the tissues enters the atrium and passes to the ventricle that then pumps the blood towards the

Cancer, What is Cancer? Besides AIDS, Cancer is another deadly human di...

What is Cancer? Besides AIDS, Cancer is another deadly human disease of our times about which people are panicky all over the world. It is estimated that one in every three per

Biosecurity in poultry health management, B i osecurity in Poultry Health...

B i osecurity in Poultry Health Management Biosecurity includes all the measures that are taken to prevent infection to individual, material and environment from the pathogen

Percentage ratio of ash in honey, Q. Percentage ratio of ash in honey? ...

Q. Percentage ratio of ash in honey? Standards allow ash content in honey up to 0.5 per cent, but the ash of genuine honey seldom exceeds 0.35 per cent. It is determined by cha

Is herbivorism a form of predatism, Is herbivorism a form of predatism? ...

Is herbivorism a form of predatism? Herbivorism is a type of predatism in which first order consumers feed from producers (plants or algae). For instance, birds and fruits, hum

Explain photosynthetic prokaryotes and mitochondria, What evidence strength...

What evidence strengthens the hypothesis that chloroplasts could have been photosynthetic prokaryotes and mitochondria could have been aerobic prokaryotes? In fact that the chl

Shivering - heat production, Shivering - Heat Production The mechanis...

Shivering - Heat Production The mechanism of thermogenesis with which we are more familiar is shivering and all adult birds and mammals seem to use these mechanism. Shivering

Explain about human digestive system, Which organs of the body are part of ...

Which organs of the body are part of the human digestive system? The digestive system, also called as "systema digestorium", or gastrointestinal system, is composed of the dige

Why is it important to study biology, Why is it important to study biology?...

Why is it important to study biology? By studying biology, you can create informed decisions on issues that impact you and society, like environmental issues, health, and tech

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