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

Indian tick typhus, Indian tick typhus Indian tick typhus (Mediterrane...

Indian tick typhus Indian tick typhus (Mediterranean spotted fever) is a tick-borne rickettsial infection caused by Rickettsia conori and is characterized by fever and a chara

Apsirin determination, Indirect determination: By determining the weight...

Indirect determination: By determining the weight of the filler on the dried filter paper you can calculate the weight of aspirin in each tablet: weight of acetylsalicylic ac

Cobalt (co) - micronutrients, Cobalt (Co) - Micronutrients The Co conc...

Cobalt (Co) - Micronutrients The Co concentration in the dry matter of plants grown in soil normally lies around 0.02 to 0.5 ppm. In soils the content varies from 1 to 40 ppm.

Complications of exchange transfusion, Complications of Exchange Transfusio...

Complications of Exchange Transfusion i) Infection of umbilical vessels and systemic injection related to blood transfusion like malaria, CMV, AIDS and hepatitis B. ii) O

Define the term underweight, Define the term Underweight? Just as overw...

Define the term Underweight? Just as overweight is the result of a positive energy balance irrespective of the etiology, underweight results when the energy balance is negative

Cranium, need images of cranium

need images of cranium

Mollusca, family ,genus, class order , species of mollusca

family ,genus, class order , species of mollusca

What is the formation of atherosclerosis plaques, Which of the following le...

Which of the following leads to the formation of atherosclerosis plaques? -uptake of oxidized LDL particles by macrophase -non specific interactions between LDL particles

What are the three major types of rna, Q. What are the three major types of...

Q. What are the three major types of RNA? What is meant by heterogeneous RNA? Messenger RNA, or mRNA, transfer RNA, or tRNA, and ribosomal RNA, or rRNA, are the three main type

Which term explains flow characteristic of blood, Which of the below terms ...

Which of the below terms is used to explain the study of factors which influence flow characteristics of blood as it moves through the body? Is it: a) Anginology b) Hemodyna

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