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!
Evolution of Metazoa
The sponges, coming under phylum Porifera are the closest to Protista, and can perhaps be regarded even as a colony of protists rather than being multicellular. No other group has evolved from them. The coelenterates consisting of the Cnidaria and the Ctenophora, which are both diploblastic and primarily radially symmetrical, can be regarded as truly the most primitive of the Metazoa. They have evolved from the ancestral planuloid metazoans as an offshoot:
Figure: Phylogeny of the animal kingdom
The Platyhelminthes (flatworms) have also evolved from planuloid ancestor. They do not have a coelomic cavity (acoelomates) but the mesoderm is cellular, they are triploblastic and are bilaterally symmetrical. This group and all higher Metazoa can be grouped as Grade Bilateria.
The pseudocoelomates phyla which include the nematodes and the rotifers are supposed to have evolved as an offshoot from the flatworms.
The Eucoelomata constitute the remainder of the Metazoa. The acoeloid flatworm like ancestors have given rise to two main stocks:
Results: Early mortality for tricuspid valve replacement is around six per cent. But depending on the patient's class of symptoms and the number of concomitant procedures, this c
Prophase This is the first and longest phase of mitosis .At its beginning all 10 nm segments of chromatids (= chromonemata) of the duplicated chromatin fibres of interph
What are peristaltic movements? What is their role in human digestion? Peristalsis is the process of synchronized contractions of the muscular wall of the digestive tube. Peris
Aging population is an important factor to be considered in implant dentistry. Life expectancy has increased significantly past the age of retirement. Social pleasures continue thr
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Define the term - Hemiplegia The characteristics of hemiplegia (again, hemi means "half") are loss of voluntary movements on one side of the body, changes in postural tone, and
heating a food sample with Benedict''s solution is a test for...
Determine the reliability of the battery The issue of reliability of the battery has been addressed, with reasonably successful results. Clinical interpretation of the battery
Question 1: Show the procedures for filing a 510(k) application and a Pre-market approval application for medical devices in the USA. Show out the procedures for filing a
porifera characteractericts
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