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.
state 5 advantages and disadvantages of protozoa
Reptiles - Regeneration in Vertebrates Among reptiles, the lizards like the Gecko Hemidactylus flaviviridis and Anolis carolinensis can again generate their tail, following au
Q. Illustrate Mitral Valve Orifice Area? The normal mitral valve orifice in an adult is 4-5cm 2 when the valve is completely open in diastole. When the mitral valve orifice ar
Q. Why can mitochondria be considered the power plants of the aerobic cells? Mitochondria are the "power plants" of aerobic cells because within them the final stages of the ce
Describe MS Murmur in Diastolic Murmurs briefly? Characteristic: Low pitched, rumbling and diastolic murmur, loudest at apex with patient in left lateral decubitus, with pre
Non-viral vectors Viral vectors are highly efficient but when it comes to large scale production at the commercial level, non-viral serve as a better choice. These methods p
1. You are observing adsorption of a virus to the host cell, it uses long leg-like structures, what are they called?
What is Gum ghatti Gum ghatti, also known as Indian gum, is amorphous, translucent exudates of the Anogeissus latifolia tree of the Combretaceae family. Gum Ghatti is composed
Define Criteria for Assessment of Vitamin D Status? You may recall the events involved in calcium homeostasis described earlier in this section. We studied that sufficient 25-O
When coal is carbonized coke is formed along with coal gas. 1300 0 C Coal coke + coal gas
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