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

Condition type of change to be transmitted to the offspring, What are the s...

What are the situations in which the environment can alter the genotype of an individual? What is the condition for this type of change to be transmitted to the offspring? The

Objectives of the earth pressure and retaining structures, What are the obj...

What are the objectives of the earth pressure and retaining structures? After knowing all concepts about the same you should be able to learn: a. Know the field situations w

Accident proneness, Accident Proneness The close observation of accid...

Accident Proneness The close observation of accident causation theory brings out this fact that most accidents can be traced to error on the part of a number of individual em

Molluscs., what are the economic and ecological importance of molluscs

what are the economic and ecological importance of molluscs

Explain the proteins stabilize emulsions, Explain The proteins stabilize em...

Explain The proteins stabilize emulsions The proteins stabilize emulsions and contribute  physical  and rheological properties,  like thickness,  viscosity, elasticity   and  r

How to reduce calorie intake from fat, How to reduce calorie intake from fa...

How to reduce calorie intake from fat? Efforts should be made to increase the nutrition knowledge of the general public through mass media. The foods with lower fat co

Wetlands - lentic ecosystems, Wetlands - Lentic Ecosystems Wetlands a...

Wetlands - Lentic Ecosystems Wetlands are permanently or periodically water covered areas. They can be defined as submerged or saturated lands either artificially or naturall

Social determinants of health - transport, Social Determinants of Health - ...

Social Determinants of Health - Transport Rising worldwide incomes have led to a massive use of automobiles and in particular cars. Cars are seen as a threat to health because

How might stem cells be used to treat brain diseases, How might stem cells ...

How might stem cells and other tools of "regenerative medicine" be used to treat brain diseases? Fuelled by the hope which stem cells may have the capacity to rebuild virtually

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