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

Hydrostatic skeleton, Hydrostatic Skeleton The functioning of the hyd...

Hydrostatic Skeleton The functioning of the hydrostatic skeleton in an animal depends upon the musculature being arranged around an enclosed volume of fluid. After that, cont

Respiration in fishes, RESPIR A TIO N IN FISHES - Respiratory org...

RESPIR A TIO N IN FISHES - Respiratory organs are gills. In elasmobranchi 5-7 pairs of gills present, spiracles present. In Teleostomai 4 pairs gills present, covered

Results-ross operation--surgical techniques, Results: The risk of isolate...

Results: The risk of isolated aortic valve replacement is 3-4 per cent. The long term survival for 5, 10 and 15years is 75 per cent, 60 per cent and 40 per cent respectively. The

Define briefly about the conjugated proteins, Define briefly about the Conj...

Define briefly about the Conjugated Proteins? Conjugated proteins are made up of simple proteins combined with a non- proteinous substance. The non-proteinous substance is know

#biology tutor title.., When nd how i can srt my online work in this site q...

When nd how i can srt my online work in this site question #Minimum 100 words accepted#

Digestive system of class asteroidea, Digestive System of Class Asteroidea ...

Digestive System of Class Asteroidea Most asteroids are scavengers or carnivores and feed on snails, bivalves, polychaets, other echinoderms, fish, sponges, sea anemones and p

Neurons - nervous system, Neurons - Nervous System Although neurons oc...

Neurons - Nervous System Although neurons occur in a great variety of sizes and morphological forms, they have a basic plan of structure representing certain common characteri

Osmoregulation, how is water lost from respiratory surface

how is water lost from respiratory surface

Define absorption of calcium from dietary calcium supplement, Define Absorp...

Define Absorption of Calcium from dietary calcium supplements? Absorption from dietary calcium supplements is important to know, since they are almost universally recommended f

What is the tentative treatment planning, Tentative treatment planning ...

Tentative treatment planning Once the initial data has been analyed and comprehensive diagnosis and charting of the condition of the mouth has been done, you should formulate 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