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:
Q. What is Glycosylated Haemoglsbin? Glycosylated haemoglobin values give important diagnostic inferences regarding the recent past of a diabetic i.e. how well he/she managed t
Generalised Seizures Generalised seizures are bilaterally symmetrical without focal onset. One subtype, the grand mal attack, is characterised by loss of consciousness and by s
SUPERNUMERARY OR ACCESSORY CHROMOSOMES Wilson (1905) discovered them in Matapodium insect. Very small Chromosomes present in nucleus in addition to normal number of Chr
What are universal donors and universal recipients concerning the ABO blood system? Universals donors of the ABO blood type system are the individuals of the type O. Type O blo
Q. What are the phases into which photosynthesis is divided? Photosynthesis is divided into the photochemical phase or light reactions and the chemical stage.
respiration & its types
i dont know how to start
Q. What are the main functions of the cytoskeleton? As the name indicates, the cytoskeleton is accountable for the support of the normal shape of the cell it also acts as a fac
Q. What do you mean by Subxiphoid Long Axis Sweep? This sweep begins with keeping the transducer at subxiphoid region, positioning directly posterior with marker pointing towar
Define Drug effects on Vitamin and mineral metabolism? Vitamin and mineral metabolism: Micronutrients are required as cofactors or coenzymes in many metabolic pathways, includi
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