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

How low birth weight cause protein energy malnutrition, How Low Birth Weigh...

How Low Birth Weight cause Protein Energy Malnutrition? The beginning of PEM in children starts in US from the time of their birth. At least a third of the Indian children are

Define why the virginia opossum is considered a generalist, Define why the ...

Define why the Virginia opossum is considered a generalist and the koala is considered a specialist. The opossum feeds on almost anything, whereas the koala feeds only on the l

What are uses of hydrocolloids for health, Uses of Hydrocolloidsfor health ...

Uses of Hydrocolloidsfor health Hydrocolloids, together with other dietary fibres are increasingly being seen as contributing to a number of health effects. Some of the hydroco

How nutritional status affects the bmr, How Nutritional status affects the ...

How Nutritional status affects the BMR? Under nutrition and starvation are the factors which require consideration. Prolonged under nutrition or starvation causes a reduction o

How water content influence the rs content, How Water content Influence the...

How Water content Influence the RS content? The yield of RS formed in heat-moisture treatment is closely related to water content, which may be an inherent component of food or

What do you mean by herbaria and museums, Q. What do you mean by Herbaria a...

Q. What do you mean by Herbaria and Museums? A herbarium is a collection of pressed and dried plants arranged according to some valid system of classification and available for

Determine the various neurobehavioural characteristics, Determine the vario...

Determine the various neurobehavioural characteristics Contemporary views of brain function tend to conceptualise localisation in interaction with a number of developmental and

Maturation promoting factor, • Cyclins accumulate during the G1, S, and G2 ...

• Cyclins accumulate during the G1, S, and G2 phases of the cell cycle. • By the G2 checkpoint (the red bar in the figure), enough Cyclin is available to form MPF complexes (aggre

Freshwater animals, Freshwater Animals In Figure you have seen that th...

Freshwater Animals In Figure you have seen that the body fluids of freshwater animals are hyperosmotic to their aqueous surroundings. This results in two-kinds of osmotic prob

How dna-rna hybridization occurs, Q. How DNA-RNA hybridization occurs B...

Q. How DNA-RNA hybridization occurs Both DNA and RNA are able to form hybrids in solution with other RNA or DNA molecules which have complementary base pairing. Double-stranded

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