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!
Origin and Evolution of Metazoa
Most of the early metazoans were soft bodied and so their fossils are rare. The extremely fragmented fossil record does not shed any specific light on their origin. Therefore, 'most of the explanations on their origin are based on their embryology and -comparative morphology. A series of theories have been put forward to explain the origin of multicellular metazoans from unicellular organisms. Of these, three principal theories could be considered.
1) Syncytial Theory: That the ancestral metazoans have arisen from a multinucleate. ciliate by compartmentalization or cellularization.
2) Colonial Theory: That the ancestral metazoans have arisen from colonial flagellates by cellular specialisation and interdependency.
3) Polyphyletic Theory: That the metazoans have arisen from more than one group of organisms.
Q. What is the lasting form in the gametophyte, pteridophytes or the sporophyte? How can it be compared to bryophytes? The lasting form in pteridophytes is the diploid (2n) spo
Primary Prevention: Primary prevention should have the following goals: i) Ascertaining at the risk population and the high risk situations where stressful life events a
What is Tetralogy of Fallot ? Figure: Anatomical location of tetralogy of fallot Indications for Surgery : The diagnosis of tetralogy is considered as an indicatio
In humans, attached earlobes are a dominant feature over free earlobes while hypertrichosis of the ear is a holandric (Y-linked) feature. A person with attached earlobes and extens
mORPHOLOGY OF AMOEBA AND ITS ADAPTATIONS
Why do plants need to exchange gases with the environment? Plants require to do gas exchange because they create aerobic cellular respiration (like animals) and they need to ge
The risk for IE among IV drug abusers, 2 to 5 per cent per patient- year, is estimated to be several fold greater than that of patients with rheumatic heart disease or prosthetic v
Define some Beneficial Effects of Fungi? 1. These act as decomposers and can degrade complex organic molecules in dead plants and animals to simple organic compounds and inorga
Give three examples of human disorders which are caused by the action of a single pair of alleles. In every case say whether the harmful allele is dominant or recessive to the non-
What are the consumer and producer surplus? Consumer and producer surplus: At equilibrium P 1 Q 1 (as point B, here demand equals supply) Consumer surplus:
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