Metazoa, Biology

Assignment Help:

Metazoa

In the two kingdom classification, the unicellular 'animals' used to be clubbed together under a single phylum Protozoa that constituted sub-kingdom - Protozoa. The rest of the animals, all multicellular, were grouped under the sub-kingdom Metazoa under various phyla (the corresponding grouping for plants was Protophyta and Metaphyta). However, under the present concept of Five Kingdom Classification, this grouping has no relevance. Still, we often continue to use the term Metazoa to refer to the Animalia of the five kingdom classification. In this we start with an explanation of the levels of body organization in animals and the basic animal body plan. However, diverse the different invertebrates and vertebrates may appear to the eye, it is possible to group them in four master body plans.

These are the unicellular plan, the cell aggregate plan, blind sac plan and tube within a tube plan. The protozoan fall into the first category and the rest three structural plans are seen in the metazoans. We next list out the characteristic features of metazoans. We shall also discuss those features that are considered of fundamental importance for describing and understanding the structure and classification of any animal. These characters are:

  • Cleavage patterns and number of germ layers it has been derived from
  • Its body symmetry
  • Nature of body cavity
  •  Segmentation and cephalisation

 


Related Discussions:- Metazoa

Sucession, what is the model of tolerence mpdel of sucession

what is the model of tolerence mpdel of sucession

Illustrate natural and phylogenetic classification, Q. Illustrate Natural a...

Q. Illustrate Natural and Phylogenetic Classification? Natural Classification Natural systems of classification reflect the situation as it might have existed in nature. T

Excretory organs, why the excretory organ of prawn is called ''green gland'...

why the excretory organ of prawn is called ''green gland''?

Mixed aortic stenosis and regurgitation, Mixed Aortic Stenosis and Regu...

Mixed Aortic Stenosis and Regurgitation :  The combined aortic valve stenosis and regurgitation may be of congenital or acquired aetiology, as in aortic stenosis. Most common

Sex-limited traits, Sex-Limited Traits Sex Limited Traits are traits ex...

Sex-Limited Traits Sex Limited Traits are traits expressed only in one sex, although the genes controlling thcm arc prcscnt as wcll as transmitted to both thc sexes. Therefore,

Define basic working of the endocrine system, Q. How does the circulatory s...

Q. How does the circulatory system participate in the functioning of the endocrine system? The circulatory system is basic for the functioning of the endocrine system and the b

Calculate micronutrient and other nutrient requirements, Calculate Micronut...

Calculate Micronutrient and other specific nutrient requirements? The recommended average daily per capita intake of various specific nutrients for typical population requiring

Is water a polar or a non-polar molecule, Is water a polar or a non-polar m...

Is water a polar or a non-polar molecule? What is the consequence of that characteristic for the function of water as solvent? Water is made of two atoms of hydrogen attached b

Define how to prevent the cancer, Define How to Prevent the Cancer? A c...

Define How to Prevent the Cancer? A continuing and urgent need is there to take all steps to prevent cancer. Cancer rates are set to increase another 50 percent by the year 202

Quantification tricuspid regurgitation-echo quantification, Quantification ...

Quantification of Tricuspid Regurgitation Echocardiography and right ventricular angiogram can quantify tricuspid regurgitation. Echo Quantification Trivial: Non susta

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