Polyphyletic theory - metazoa, Biology

Assignment Help:

Polyphyletic Theory - Metazoa

This theory was suggested by Greenheig (1959) and some other workers. According to this theory, sponges, coelenterates, ctenophores and flatworms have each evolved independently from protozoans. Sponges and coelenterates have probably arisen through colonial flagellates, while ctenophores and flatworms through ciliates or even mesozoans.

It is apparent that this theory is a compromise between the Syncytial and colonial theory.


Related Discussions:- Polyphyletic theory - metazoa

Evolution of heart in higher animals, Evolution of heart in higher animals ...

Evolution of heart in higher animals The circulatory system in higher animals has undergone several changes during evolution. The heart has become totally muscular. Th

Captive breeding - measures for species conservation, Captive Breeding - Me...

Captive Breeding - Measures for Species Conservation Species which are reduced to dangerous levels need more intensive management, and one strategy is their captive breeding.

Vertebrates, characterstics and classification of vertebrates

characterstics and classification of vertebrates

What is digestion, What  is digestion? The  ingested food material  is...

What  is digestion? The  ingested food material  is  broken down  into smaller constituents which  are assimilable  by  the  blood.  The  process  through which  the major nutr

Why plant cycle know as alternation of generations, Q. Why is the plant lif...

Q. Why is the plant life cycle known as alternation of generations? The plant life cycle is called as alternation of generations because in this cycle there are two different f

Male reproductive disorders-blockage of ducts, Blockage of ducts In so...

Blockage of ducts In some bulls there is a blockage of the transport of sperm through the epidydimis usually caused by a congenital non-patency of some part of the vasa effere

Non-rapid-eye-movement sleep, Stage 1 sleep: As an individual becomes drows...

Stage 1 sleep: As an individual becomes drowsy, and enters stage 1, alpha wave decreases and theta waves appear. Theta waves with a frequency of about 6 to 8 cycles per second are

Protozoa, Locomotion,nutrition and reproduction in ptotozoa

Locomotion,nutrition and reproduction in ptotozoa

Build vocabulary, what is the opposite of yield? A.grow B.attack C.ask D.an...

what is the opposite of yield? A.grow B.attack C.ask D.answer

What are the main components of the cytoskeleton, The cytoskeleton is a net...

The cytoskeleton is a network of very little tubules and filaments spread throughout the cytoplasm of eukaryotic cells. It is made of microtubules, microfilaments and intermediate

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd