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

High energy fixation - nitrogen fixation, High energy fixation - Nitrogen F...

High energy fixation - Nitrogen Fixation Through cosmic radiations, lightning, volcanic activity and meteorite trails which provide the high energy needed to combine atmospher

Define foam spray drying method, Define Foam Spray Drying Method? This...

Define Foam Spray Drying Method? This is an extension of spray drying and involves the use of gases dissolved under pressure prior to spraying. The main advantage is that the

Water, Water Water usually forms about 50% to90% part of living protopl...

Water Water usually forms about 50% to90% part of living protoplasm. Life upon earth originated in the ocean and the conditions of that aqueous primeval environment have been r

What is ionic bonds, What is Ionic bonds ? Ionic Bonds :  Ionic bonds...

What is Ionic bonds ? Ionic Bonds :  Ionic bonds hold atoms together in crystals. They form when oppositely charged atoms, or ions, join (opposite charges attract) to equaliz

Telenursing, Telenursing Telenursing refers to the exchange of experti...

Telenursing Telenursing refers to the exchange of expertise in various areas like nursing diagnosis data over a distance. It is divided into the following categories: a)

What is pus, What is pus Pus is a residual of the inflammatory reaction...

What is pus Pus is a residual of the inflammatory reaction. It is having a mixture of fragments of dead leukocytes, infectious agents (generally bacteria) and tissues.

Forebrain - diancephalon, DIANCEPHALO N - Less visible. Occupies on...

DIANCEPHALO N - Less visible. Occupies only 1% of brain's volume. Its lumen is diocoel or III ventricle. Roof is epithalamus . On it pineal body is present. Fl

Define foaming properties of proteins, Define Foaming Properties, Binding o...

Define Foaming Properties, Binding of Flavour and Other Substances? To understand the foaming properties of proteins, we need to know some basic aspects of foam foods. Foam foo

Rna secondary structure, Most  RNA  molecules  are  single-stranded  but  a...

Most  RNA  molecules  are  single-stranded  but  an  RNA  molecule  should  hold regions  that  can  form  complementary   base  pairing  where  the  RNA  strand loops  back  on  i

Biodynamic dealing with energetic of organisms, Biodynamic: This dealing w...

Biodynamic: This dealing with energetic of organisms. Biodynamic is a method of organic farming which treats farms as unified or individual organisms, emphasizing balancing the ho

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