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

Types specimens of echpnodermata, Types specimens of echpnodermata Befor...

Types specimens of echpnodermata Before we begin the study of the selected specimens of the following echinoderms - Feather star, Brittle star, Sea urchin, Sea cucumber and Star

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

Illustrate the improper implant design, Improper Implant Design Out of ...

Improper Implant Design Out of the plethora of implant systems available it is the responsibility of the clinician to select the most suitable. In comparison of the straight cy

Purposes of patient /client records, PURPOSES OF PATIENT's /CLIENT's RECO...

PURPOSES OF PATIENT's /CLIENT's RECORDS Following purposes are served by maintaining patient's/client's records: A means of communication.  A basis on which therap

Explain the process of angioplasty, Q. Explain the process of Angioplasty? ...

Q. Explain the process of Angioplasty? Inflation of stenotic segment causes stretching of the vessel, fracture of the intimal plaque, partial disruption of the media and adven

Define requirements of zinc during pregnancy period, Define requirements of...

Define requirements of Zinc during pregnancy period? Zinc, as a mineral, was found to be associated with foetal growth and birth weight. Low plasma zinc was associated with mor

Adrenal glands, Adrenal glands There are two adrenal glands one each...

Adrenal glands There are two adrenal glands one each on the top of each kidney. Adrenal gland has two parts, the outer cortex and inner medulla. Both cortex and medull

What is hypothalamus, Which of the following is true for ventilation? A...

Which of the following is true for ventilation? A. Interneurons responsible for generating the rhythm of ventilation are located only in the hypothalamus. B. All the central

How is the extracorporeal digestion, Q. How is the extracorporeal digestion...

Q. How is the extracorporeal digestion associated to predation in arachnids? Arachnids can inoculate poison to kill or paralyze their preys using structures called chelicerae.

What is the objectives of evaluation of patient clinical, What is the OBJEC...

What is the OBJECTIVES of evaluation of patient clinical examination ? After going through this unit, you should be able to: 1. Carried out the general physics-examination; 2.

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