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 angiosperms, What is Angiosperms? Angiosperms are the second ma...

What is Angiosperms? Angiosperms are the second major group of plants that bear seeds. Angiosperms (seeds in vessels) differ from gymnosperms in that their seeds develop within

Interventricular septum, It corresponds to the anterior and inferior interv...

It corresponds to the anterior and inferior interventricular grooves. Its right side is convex and bulges to the right ventricle. The septum has a posterior border which separates

Cardiac transplantation, For patients with end-stage heart failure, cardiac...

For patients with end-stage heart failure, cardiac transplantation has become a promising therapy especially with the advent of  immunosuppressive therapy and more careful screenin

Growth rate in animals, GROWTH RATE IN ANIMALS - Growth rate is differe...

GROWTH RATE IN ANIMALS - Growth rate is different at different periods of life. Growth period in human may be studied in 5 steps - (i) Prenatal - In gestation period fo

What is the virus that causes flu, Q. What is the virus that causes flu? Wh...

Q. What is the virus that causes flu? Why doesn't the body produce permanent immunity against that virus? How does the vaccine against flu work? Flu is a disease caused through

What are vectors of parasites, Q. What are vectors of parasites? The Ve...

Q. What are vectors of parasites? The Vectors of a parasite are organisms can transport the parasite during stages of its life cycle mediating the infection of other hosts. For

How is sound vibration captured by the tympanum, Q. How is the sound vibrat...

Q. How is the sound vibration captured by the tympanum transmitted through the ossicular chain of the middle ear? The acoustic transmission from the middle to the external ear

In dental traumatology-Pulp Tissue revascularization, In Dental Traumatolog...

In Dental Traumatology Traumatic injuries in young kids (8 to 14 years old male > female)  are commonly nowadays. Dental traumatic injuries are mostly in anterior teeth

Explain principle osazone test or phenylhydrazine reaction, Explain Princip...

Explain Principle Osazone Test or Phenylhydrazine Reaction? Phenylhydrazine reacts with carbonyl compounds in neutral or slightly acidic medium to give phenylhydrazones. These

Explain starch - tests for presence of exoenzymatic activity, Explain Starc...

Explain Starch - Tests for the Presence of Exoenzymatic Activity? Starch is a polymer of glucose linked together by glycosidic bonds. Microorganisms produce hydrolytic enzyme a

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