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 are the major human diseases caused by virus, Q. What are the major hu...

Q. What are the major human diseases caused by virus? Among diseases caused by virus are common cold, variola (considered eradicated nowadays), mumps, measles, rubella, AIDS, t

Female reproductive system, FEMALE REPRODUCTIVE SYSTEM - In female mamm...

FEMALE REPRODUCTIVE SYSTEM - In female mammals the female reproductive system characteristically comprises of the ovary, uterus, placenta, vagina and vulva.

Access through the crown-endodontics principles and practice, Access throug...

Access through the crown Advantages : -Allow for better isolation with the rubber dam -Better esthetic anf functioning. -Good coronal seal between visits Limitations : -Proc

Explain requirements and recommended dietary intake, Explain Requirements a...

Explain Requirements and Recommended Dietary Intake? A very small daily intake of vitamin C (10-15 mg/day for an adult) is required to avoid deficiency and stave off scurvy. Ho

Prevention and community action - psychoactive substance, Prevention and Co...

Prevention and Community Action: A number of  preventive action are necessary. Alcohol prevention programmes can have major effects on alcohol problem rates, and can influence

Cancer, Cancer ;  Cell  division , like  all other  biological  processes,...

Cancer ;  Cell  division , like  all other  biological  processes,  is under  genetic control. Certain  genes must regulate the processes  of cell growth  and division  in respons

Cell membrane, CELL MEMBRANE It is biological, thin, elastic, flexib...

CELL MEMBRANE It is biological, thin, elastic, flexible & selective permeable membrane. Term "Cell membrane" was coined by Negeli & Crammer 1855. Term " Plasma membr

Explain highly active antiretroviral therapy, Highly active antiretroviral ...

Highly active antiretroviral therapy (HAART) - The treatment of HIV infection requires combination therapy known as highly active antiretroviral therapy (HAART) along with inte

Molluscus - hormones in growth and reproduction, Molluscus - Hormones in Gr...

Molluscus - Hormones in Growth and Reproduction We know quite well about the endocrine mechanism of growth and reproduction in the freshwater snail Lymnaea stagnalis. This is

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