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

Respiratory system - developmental changes, Respiratory System - Developmen...

Respiratory System - Developmental Changes after Birth The new-born's lungs are collapsed and need powerful breaths to inflate them; airways too are small, offering remarkable

Evolution, species dynamicsresemble what

species dynamicsresemble what

Explain advantages of using bacteria as a source of protein, Bacteria:- ...

Bacteria:- Advantages High yield of protein (60-80%) Can be grown on paraffin, cellulose waste and molasses. Growth rate is fast. Disadvantages  If the bacteri

Gills - respiration, Gills - Respiration Gills are highly vascularise...

Gills - Respiration Gills are highly vascularised extensions of gas exchange membranes. The simple type may be extension of the body surface as in sea-slugs, sea stars and ma

What is the difference among plasma membrane and cell wall, Plasma membrane...

Plasma membrane and cell wall is not the similar thing. Plasma membrane, also known as cell membrane, is the outer membrane common to all living cells and it is made of a phospholi

Describe the important factors of hand washing, Describe the important fact...

Describe the important factors of Hand washing Hand washing is an important practice to follow before doing any procedure for the patient. The infection can be transferred

Denaturing gel, Denaturing Gel is an agarose or the acrylamide gel run und...

Denaturing Gel is an agarose or the acrylamide gel run under conditions which destroy the secondary or tertiary protein or RNA. For protein, this generally means the inclusion of

Explain the bioelectrical impedance analysis (bia), Explain the Bioelectric...

Explain the Bioelectrical impedance Analysis (BIA)? The difficulty of measuring total body water (TBW) by Isotope Dilution Method led to the search of Bioelectrical Impedance A

What is nuclear proteins , The nucleus has an inner and an outer memb...

The nucleus has an inner and an outer membrane and is perforated through 3000-4000 nuclear pores. Each pore having of a nuclear pore complex of more than 100 several proteins organ

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