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

What is the etiological agent of cutaneous leishmaniasis, What is the etiol...

What is the etiological agent of cutaneous leishmaniasis? How is the disease transmitted and what are its typical manifestations? The etiological agent of cutaneous leishmanias

State the number of nuclear dna molecules, For each of the following stages...

For each of the following stages, state the number of nuclear DNA molecules in one of your cells (i.e., 23,46, or...) and its ploidy (i.e.,n, 2n, or...). 1.) Prophase of mitosis

Definition of biological diversity, Q. Definition of Biological diversity? ...

Q. Definition of Biological diversity? Biological diversity has no single standard definition. One definition holds that biological diversity is a measure of the relative diver

Camptotheca acuminata, This species is an ornamental tree in China, and has...

This species is an ornamental tree in China, and has yielded the clinically active agents topotecan, irinotecan, and 9 -aminocamptothecin, which are semisynthetically derived from

What are the characteristics of thin gingiva, Characteristics of Thin Gingi...

Characteristics of Thin Gingiva  Highly scalloped soft tissue and bony architecture  Delicate friable soft tissue  Minimal amount of attached gingiva  Thin underlying

What is carrier protein, How does the interaction between a carrier protein...

How does the interaction between a carrier protein and the substance it transports resemble the interaction among an enzyme and its substrate? Both include the binding of a spe

Major objectives of diarrhoea, Q. Major objectives of diarrhoea? The ma...

Q. Major objectives of diarrhoea? The major objectives in the management of diarrhoea include: 1. Fluid and electrolyte replacement 2. Removal of cause (especially if inf

Implantation, IMPLAN TA TIO N - Attachement of blastocyst on the ...

IMPLAN TA TIO N - Attachement of blastocyst on the endometrium of the uterus is called implantation. Generally it occurs 7th day after fertilisation. (6-10 days). Blas

Define principle of fehling test - reduction tests, Define Principle of feh...

Define Principle of fehling test - reduction tests? Sugars that possess a free or potentially free (those that can be converted to free) aldehyde or ketonic group have a proper

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