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

Lotic ecosystems rivers, Lotic Ecosystems Rivers The lotic or flowing...

Lotic Ecosystems Rivers The lotic or flowing water habitats include rivers streams, brooks etc. The most outstanding features of such habitats is the continuously flowing wat

What is pulmonary veins in normal pulmonary vasculature, Q. What is Pulmona...

Q. What is Pulmonary Veins in Normal Pulmonary Vasculature? The right and left upper lobe or superior pulmonary veins descend lateral to the arteries, cross in front of the hil

Important causes of degradation of ecosystem, Important Causes of Degradati...

Important Causes of Degradation of Ecosystem The important causes that have lead to the degradation of the ecosystem. Deforestation Overgrazing Agriculture

Which organs form the human respiratory system, Q. What are the organs that...

Q. What are the organs that form the human respiratory system? The organs that are part of the human respiratory system can be divided into three groups: lungs, respiratory mus

Nitrogen assimilation, The next step in the nitrogen cycle is the assimilat...

The next step in the nitrogen cycle is the assimilation of inorganic nitrogen in the type of ammonia into organic nitrogen-having compounds. Total organisms assimilate  ammonia  by

Explain about single cell proteins, Single Cell Proteins (SCP)  The t...

Single Cell Proteins (SCP)  The term SCP was coined by Prof. Caroll Wilson (MIT) in 1966. It means the proteins obtained from microbial sources, i.e. algae, fungi, bacteria,

Population, Population was defined by Clarke in 1954. The term populat...

Population was defined by Clarke in 1954. The term population refers to the total number of individuals of a sp. occupying a particular geographic aera at a given time. A s

Explain procedure for the use of light microscope, Explain Procedure for th...

Explain Procedure for the use of Light Microscope? Now carry out the exercise following the steps enumerated herewith. 1. Place the microscopic slide with any specimen on th

Cell Division, What is the difference between Mitosis and Meosis?

What is the difference between Mitosis and Meosis?

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