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.
Q. Fats requirement in pectic ulcer? Fats: These delay the gastric emptying. The products of fat digestion in the small intestine stimulate entrogastrone, which inhibits gastri
If one determines the concentration of cortisol in the blood plasma to be 10 micrograms/mL and that in a 24 hour period a person excretes 10 mgs of cortisol, calculate the volume o
To ensure the building's resistance to potential earthquakes it should be configured, detailed and constructed accordingly. Any weakness in this regard may affect the building's re
Ask question #Minimum 100 words accepted
Question 1 What is autologous transfusion? Discuss how would you handle and prepare blood for autologous blood transfusion. List the advantages of autologous transfusion Qu
What is the tallness trait of a pea plant moving separately from the color trait an example of? This is an instance of Mendel's second law, the Law of Independent Assortment, w
Stabilized forms of natural colourants The mimicking of the native environment in which a natural colour exists is just one way of producing a stabilized form. In this case, th
How do calcium ions participate in muscle contraction? Why do both muscle contraction and muscle relaxation spend energy? In the muscle cells calcium ions are kept within the s
Q. What is coronary bypass graft? The Coronary artery bypass graft is a kind of surgical myocardial revascularization that is a way to provide blood to a myocardium whose blood
Chronic Aortic Regurgitation : Several factors have to be taken into account before recommending surgery. These include severity of symptoms and LV function. With evidence o
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