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!
Syncytial Theory - Metazoa
This theory suggests that the ancestral metazoan was at ,first Syncytial in structure but later became cellularised by formation of cell membranes around individual nuclei this producing a typical multicellular body. Hadzi (1953) and Hanson (1977) have been the chief proponents of this theory. As many ciliates tend to have a bilateral symmetry, the advocates of this theory maintain that the ancestral metazoan was bilaterally symmetrical similar to the present day acoelous flatworms. The theory receives support from the fact that acoelous flatworms are
Figure: Possible routes for evolution of animals
There are several objections to this theory. It ignores the embryology of flatworms in which nothing similar to cellularization occurs, nor does it explain the presence of flagellated sperms in metazoans. Perhaps the most important objection to this theory is that it assumes that .acoelous flatworms are the most primitive metazoans and therefore, presumes bilateral symmetry to be more primitive than radial symmetry and thus radial coelenterates must have been derived from bilateral flatworms. But then it is accepted that radial symmetry is more primitive than bilateral symmetry and radial coelentrates could not have evolved from flatworms.
define and explain Water vascular system with podia and tube-feet madreporite mostly present
Explain about Cyanocobalamin Cyanocobalamin occurs as dark red crystals or as a crystalline hygroscopic powder of the same colour without odour and taste. Upon standing in the
different types of animals and their respiratory organ
Q. Counselling skills used in diabetes mellitus? Information gathering is an important skill for understanding of the client. Behaviour is complex and, therefore it is importan
Artificial Inspiration : a. After artificial expiration, the rescue worker should slowly release the pressure on the back of the victim. b. This will cause the chest cavity t
what is respiration in animals ,its functions ,types of respiration
It has been shown by prospective studies that Rheumatic heart disease (RHD) is linked to the occurrence of carditis during the first episode of ARF. If the first episode is accompa
Nutritional effects Of Hemicelluloses Hemicelluloses are classified under the category of soluble dietary fibers. Hemicellulose is an indigestible complex carbohydrate that ab
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Typhoid Typhoid vaccine is recommended for travellers to developing countries in Central and South America, Africa and Asia, especially if they plan a long stay or may be livi
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd