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 choanocytes, Which one of the following statements about all the fo...

Which one of the following statements about all the four of Spongilla, Leech, Dolphin and Penguin is correct? 1. Penguin is homiothermic while the remaining three are poikilothe

Describe class holothuroidea in details, Describe Class Holothuroidea in de...

Describe Class Holothuroidea in details? Members of this Class resemble soft and squishy cucumbers lying on their sides on the bottom of the sea. On first glance, they appear n

What is the rule for the pairing of nitrogen-containing base, Q. What is th...

Q. What is the rule for the pairing of nitrogen-containing bases in the DNA molecule? And in the RNA? Is this the last question appropriate? The rule for the pairing of nitroge

Influence of lv function, Influence of LV Function :  LV functions, whethe...

Influence of LV Function :  LV functions, whether normal or impaired is important while selecting a patient for CABG and for long-term results of surgical revascularisation. If le

Sexual reproduction, SEXUAL REPRODUCTION You must be aware that reproduct...

SEXUAL REPRODUCTION You must be aware that reproduction is one of the distinguishing features of living beings. Reproduction is basically of two types: asexual and sexual. In ase

What is strobilization. elaborate., What is Strobilization. Elaborate. ...

What is Strobilization. Elaborate. The process which converts scyphostome into a strobila during the life cycle of schyphozoans, jellyfish. Transverse divisions of strobila pro

Define evolution of food processing, Define Evolution of food processing? ...

Define Evolution of food processing? 8000 - 7000 BC. Mankind first began farming, growing crops and raising animals for food instead of hunting and gathering for food.

St. jude medical valve--types of valves, St. Jude Medical Valve (SJM) :  ...

St. Jude Medical Valve (SJM) :  This is a low profile bi-leaflet valve, which was introduced in 1977. The leaflets and the housing are made of pyrolitic carbon. The currently

Explain imiquimod, Imiquimod (Aldara) This immunomodulator is FDA-appro...

Imiquimod (Aldara) This immunomodulator is FDA-approved for topical treatment of external and perianal genital warts, which are caused by papillomavirus. Gradual clearance of w

Does the fish heart pump venous or arterial blood, Does the fish heart pump...

Does the fish heart pump venous or arterial blood? The venous blood coming from the tissues enters the atrium and passes to the ventricle that then pumps the blood towards the

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