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

hormonal control of osmoregulation, This process involves the regulation o...

This process involves the regulation of the concentration of the body fluids through control of water content and salt content of the blood. If a person loses water from their bloo

Coordination and control, how is an increase in glucose concentration contr...

how is an increase in glucose concentration controlled in the human body?

Invertebrates, list any 15 characteristics of phyla protozoa

list any 15 characteristics of phyla protozoa

Explain the following terms in detail - homology, Explain the following ter...

Explain the following terms in detail - Homology, Homologous ? Structures that have a similar evolutionary origin however different functions. The wing of a bat and a whale's fl

Pesticides - danger to wildlife, Pesticides - Danger to Wildlife Anoth...

Pesticides - Danger to Wildlife Another recently realised danger to wildlife in many parts of the world has come from the development of more effective pesticides. As agricult

Explain the regulation of breathing and blood pressure, Which is the brain ...

Which is the brain region responsible for the regulation of breathing and blood pressure? The neural regulation of breathing, blood pressure and other physiological parameters

How to use a key, Q. How to Use a Key? The use of a key is analogous to...

Q. How to Use a Key? The use of a key is analogous to travelling a high way, that forks repeatedly, each fork having roadside directions. If a traveller follows the proper dire

Chemical agents available for sterilization, Q. Chemical Agents Available f...

Q. Chemical Agents Available for Sterilization? Chemical Agents: these include the following: Alcohols: ethyl alcohol, isopropyl alcohol, trichlorobutanol Aldehydes: f

Precautions for detection of number of bacteria in milk, Explain the Precau...

Explain the Precautions for Detection of Number of Bacteria in Milk? 1. Make a thin film of milk on the slide. 2. Do not over stain with methylene blue.  If over staining ha

Characteristic feature of respiration, Characteristic Feature of Respiratio...

Characteristic Feature of Respiration From our opinion we may say that the characteristic feature of respiration is the intake of oxygen and the output of the carbon dioxide.

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