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

Write details of botanical source, Question 1: Write details of Botanic...

Question 1: Write details of Botanical source, common name, part of plant used, chemical constituents and uses for the given drugs: a) Momordica charantia b) Moringaoleifera c

Female reproductive system - fallopian tube, F ALLOPIAN TUBE - Ferti...

F ALLOPIAN TUBE - Fertilisation occur in it. 10-12 cm long muscular tube. It is supported by double fold of peritonium. It shows 4 regions - (i ) Infundibulum - Bro

What is teratology, Teratology: It is the study of abnormal embryos. In ot...

Teratology: It is the study of abnormal embryos. In other words teratology is the study of abnormalities of physiological development. It is often use as the study of birth defect

Fundamental cardiac unit, The fundamental contractile unit is the sarcomere...

The fundamental contractile unit is the sarcomere. Each muscle cell apart from the nucleus, mitochondria and other structures contains parallel fibrils. Sarcomere is a subunit of t

Upwelling zones of high biological productivity, Upwelling zones of high bi...

Upwelling zones of high biological productivity are found along the western coasts of the major continents. What causes this upwelling? a- cold currents moving from the equator tow

Sex-limited traits, can u show the different activities on the topic

can u show the different activities on the topic

Explain astrand cycle test, Explain Astrand Cycle Test? This is a sub m...

Explain Astrand Cycle Test? This is a sub maximal test done on cycle ergo meter. In this test, comparatively lower wattages are set. For example, for males less than 35 years o

Why waste considered major environmental issues, Q. Why is waste considered...

Q. Why is waste considered one of the major environmental issues? The environmental problem regarding waste worsens with industrial development and the global growth of consump

Explain hardy weinberg equilibrium., MN blood group in humans is under the ...

MN blood group in humans is under the control of two co-dominant alleles M and N. Blood typing results of a population having of 1349 individuals showed that:  -  363 persons h

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