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

Why iodine is important for human body, Why Iodine is Important for Human B...

Why Iodine is Important for Human Body? Iodine is an essential constituent of the thyroid hormones: thyroxine (T 4 ) and triiodothyronine (T 3 ), which have a key role in growt

Symptomatic patient-chronic mitral regurgitation, Symptomatic patient: Sy...

Symptomatic patient: Symptomatic patient (class 11, 111 or IV) with severe MR and normal left ventricular function (EF > 0.6) and end systolic dimension of LV

Explain canal obstruction - non-surgical endodontic, Explain Canal Obstruct...

Explain Canal Obstruction - Non-surgical Endodontic Retreatment     File work shorter than the normal apical and feel a great resistance to reach the true length a. A retain

Stage of meiosis, briefly describe the eggs and follicles, in rabbit

briefly describe the eggs and follicles, in rabbit

Determine the fructose to glucose ratio in honey, Q. Determine the fructose...

Q. Determine the fructose to glucose ratio in honey? This activity will help you to: • check the given samples of honey for any adulteration with commercial sugar

Natural selection, Darwin put fort the notion of the survival of the fittes...

Darwin put fort the notion of the survival of the fittest. How do we define 'fittest'? The answer usually given is those who survive. So you can readily see that this is a circular

Photosynthesis, Photosynthesis Photosynthesis - the process by which p...

Photosynthesis Photosynthesis - the process by which plants utilise energy from sunlight to convert carbon dioxide and water for the synthesis of sugar. This sugar can then be

Anatomical reason for the left bronchus to be more elevated, Q. What is the...

Q. What is the anatomical reason for the left bronchus to be more elevated than the right bronchus? Why in most cases of aspiration of foreign material by children is the object fo

Insulin binding to insulin receptors in the plasma membrane, Insulin bindin...

Insulin binding to insulin receptors in the plasma membrane of a A. liver cell will lead to an increase in the intracellular amounts of cAMP in the liver cell. B. beta-islet

Define nutritional requirements of fats and oils, Define Nutritional Requir...

Define Nutritional Requirements of Fats and Oils? As with the other macronutrients, we do compute requirements of visible fats too for all age groups and give guidelines for se

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