Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Mosaic and Regulative Eggs
Eggs as well as early cleavage embryos are occasionally divided into two categories:
i) Mosaic or determinate embryos and
ii) Regulative or indeterminate embryos.
The terms mosaic and regulative relate to the time for which the restrictions in development are imposed on the blastomeres. For instance, the embryos of tunicates related to mosaic or determinate category. In these organisms the various blastomeres become restricted to make only specific structures as soon as they are formed or during the first few cleavages. In other words, the respective fates of dissimilar blastomeres are finally determined early in mosaic embryos. As a result, the removal or loss of specific blastomeres cannot be compensated by the other blastomeres and the embryos will be defective in structures that are normally derived from the missing blastomeres.
In regulative or indeterminate embryos the restrictions on blastomeres take place later in development. Amphibians and sea-urchins belong to this category. Because the cell fate of blastomeres is lastly determined later, any removal or destruction of blastomeres early in development can be compensated by the other blastomeres that are able to form all the structures. It is also believed that the differences between mosaic and regulative embryos are directly connected to the extent of their usage of extrinsic and intrinsic mechanisms for cell determination. The mosaic embryos depend on ooplasmic determinants, i.e. intrinsic factors for cell fate determination. In contrast, the regulative embryos mostly rely upon extrinsic factors derived from cell interaction for cell determination.
Q. Explain about Microwave irradiation? Most micro-organisms are destroyed by the action of microwave of a frequency of about 2450 MHz and a wavelength of 12.24 cm. The water c
Question 1 Write a short note on the following 1 Class polychaeta
special components and features
Explain the Procedure for Morphological Study of Fungi? Now carry out the exercise, following the steps enumerated herewith: 1. Prepare a humid chamber by placing two-three
Extracellular Aging The basic components of extracellular space are mucopolysaccharides and fibrous proteins, particularly collagen and elastin. These proteins are synthesised
RADIOGRAPHY You have read in GNM courses about radiographical examination. In this text the discussion will be on the following radiographical tests. Chest Roentgenogram
Determine the maximum crop yield In determining maximum crop yield it was thought that a given plant let us say corn, is only inherently capable of producing a given amount of
Erythrocytes or red blood cells: These are otherwise called Red Blood cells or corpuscles. These are the most numerous cells in the blood.There are about 4.5 to 5.5x 10 9
describe each and every step in nutrition in animals?
Galactose Metabolism Galactose goes to the liver via portal blood and is phosphorylated by galactokinase togalactose- 1 -phosphate (GIP) using ATP as a phosphate donor as s
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd