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

Explain about the terms - bursae and captacula, Explain about the terms - b...

Explain about the terms - bursae and captacula? Paired water-filled sac located at base of each arm of a brittle star. Cilia in bursae circulate water. Its surface is significa

What do you mean by osseous cavity, Q. What is the osseous cavity where the...

Q. What is the osseous cavity where the pituitary gland is located? The hypophysis or pituitary gland is located in the sella turcica of the sphenoid bone (one of the bones in

Explain dough formation, Explain Dough Formation   Gluten is the prote...

Explain Dough Formation   Gluten is the protein found in wheat. A unique property of gluten proteins of wheat grain endosperm (and  to  a   lesser extent of rye and  barley  g

Write the definition of counselling, Q. Write the definition of counselling...

Q. Write the definition of counselling? The counselling process, involves various steps in a sequence as given below: 1. Rapport-Building 2. Locating the Problem 4. Pl

Cell Help?, What is the mRNA sequence to this DNA sequence : Guanine, cyto...

What is the mRNA sequence to this DNA sequence : Guanine, cytosine, adenine, adenine, thymine, guanine

Of which type of defense cell do worm infections, Q. Of which type of defen...

Q. Of which type of defense cell do worm infections stimulate the multiplication? The main leukocytes that generally participate and multiply in the defense against worm infect

Describe class ophiuroidea in general way, Describe Class Ophiuroidea in ge...

Describe Class Ophiuroidea in general way? Brittle stars have a central disc with five long, thin, flexible arms that can be detached from the body at will in times of danger.

What is the explanation for the bleeding, Q. What is the explanation for th...

Q. What is the explanation for the bleeding that accompanies menses? The hemorrhage that accompanies menses occurs because the endometrium is a richly vascularized tissue and t

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