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

Name the enzyme present in saliva, Name the enzyme present in saliva and sa...

Name the enzyme present in saliva and say what type of food it acts on.   The enzyme in saliva is salivary amylase and it acts on starch.

Describe in detail about the cytoplasm, Describe in detail about the Cytopl...

Describe in detail about the Cytoplasm Cytoplasm also possesses a number of dense granular elements (about 25,000 per cell) called the ribosomes, which are the sites of protein

Does ascaris lumbricoides present an intermediate host, Q. Does Ascaris lum...

Q. Does Ascaris lumbricoides present an intermediate host? An Ascaris is a monoxenous parasite, its life cycle is dependent only on one host and so it doesn't have intermediate

Explain why this essential that muscle cells, Explain why it is essential t...

Explain why it is essential that muscle cells, during anaerobic respiration, convert pyruvic acid (pyruvate) into lactic acid, even though the conversion results in an accumulation

Regulation of glycogenesis, Regulation  of Glycogenesis Glycogen syntha...

Regulation  of Glycogenesis Glycogen synthase,  the key enzyme in glycogenesis, is activated by insulin and glucose and inhibited by CAMP.

Excretory system, what is the excretory system of a crab?

what is the excretory system of a crab?

How age factors affect the requirement of protein, How age factors affect t...

How age factors affect the requirement of protein? Age: Protein in excess of maintenance needs is required, when a new tissue is being fornled. Certain age periods, when growth

Enzyme activity, Enzyme Activity Enzymes are biomolecules which catalyz...

Enzyme Activity Enzymes are biomolecules which catalyze (i.e. increase the rates of) chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules

Explain what is cyanosis and polycythemia, Explain what is Cyanosis and pol...

Explain what is Cyanosis and polycythemia? Cyanosis and Polycythemia: Central cyanosis involving the mucous membranes and trunk along with the lips and extremities in absence

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