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

What is the antagonism of the sympathetic, What is the antagonism between t...

What is the antagonism between the sympathetic and the parasympathetic neural actions? In general the actions of the sympathetic and the parasympathetic are antagonistic, i.e.,

Anticoagulants, ANTICOAGULANTS (a ) Heparin (hepar = liver) . It is ...

ANTICOAGULANTS (a ) Heparin (hepar = liver) . It is synthesized by mast cells of connective tissue and liver cells. It is a heteropolysaccharide. It increases the effectivit

Explain clinical dietitians, Explain Clinical dietitians Clinical dieti...

Explain Clinical dietitians Clinical dietitians, sometimes called therapeutic dietitians, are associated with health care institutes, hospitals and nursing homes. Depending on

Ameoba, locomotion in amoeba

locomotion in amoeba

Extravascular compression, Most of the coronary blood flow to the left vent...

Most of the coronary blood flow to the left ventricular myocardium occurs during diastole. Thus the contracting heart obstructs its own blood supply. The systolic compressive force

The subunit polypeptides might likely be found, The quartenary structure of...

The quartenary structure of a holoenzyme contains four long polypeptide subunits composed of non-polar, polar and charged amino acids. All subunits are properly folded and function

Explain about rna molecules, Explain how early RNA molecules might have bee...

Explain how early RNA molecules might have been able to respond to natural selection. Every RNA molecule might have competed with slightly dissimilar RNA molecules for nucleoti

Molybdenum and vanadium, Molybdenum and Vanadium - Inorganic Nitrogen and S...

Molybdenum and Vanadium - Inorganic Nitrogen and Sulphur Metabolism Molybdenum must be available in nature in order to meet the demand of Mo for the formation of nitrogenase n

Subtropical rain forests - ecosystem, Subtropical rain forests - Ecosystem ...

Subtropical rain forests - Ecosystem In regions of fairly high rainfall but less temperature differences between winter and summer and broad-leaved evergreen subtropical biome

Foraminifera, Foraminifera is the single-celled protists which secrete a s...

Foraminifera is the single-celled protists which secrete a shell or test. This is the accumulations of the shells of dead foraminifera and the other microscopic sea creatures form

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