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

Strategies for genetic characterization and conservation, Strategies for ge...

Strategies for genetic characterization and conservation - During last 20 years concerted efforts have been made to create awareness among all the developmental organizations in th

Zoology, type study of polystomella

type study of polystomella

Nutritional management in inflammatory bowel disease, Q. Nutritional Manage...

Q. Nutritional Management in Inflammatory Bowel Disease? Adequacy of nutritional needs and minimizing stress on the inflamed or narrowed segment of the bowel are the main princ

Define corneal scar - micronutrient deficiencies, Define Corneal Scar - Mic...

Define Corneal Scar - Micronutrient Deficiencies? The corneal ulcer, on healing, leaves a white scar, which may vary in size depending upon the size of the ulcer. When the scar

Types of glials cells and their functions, Types of Glials Cells and their ...

Types of Glials Cells and their Functions In the nervous tissue, besides the nerve cells there is one other cell type -the neuroglia which is present in large numbers and occu

Explain about sex chromosomes, What is the other name given to sex chromos...

What is the other name given to sex chromosomes? Sex chromosomes are also known as allosomes (the other chromosomes that are not sex chromosomes are known as autosomes).

What is ezetimibe, It is a newer agent that inhibits cholesterol absorption...

It is a newer agent that inhibits cholesterol absorption by the enterocyte. It reduces cholesterol absorption by the enterocyte. It reduces cholesterol absorption by 23 per cent-50

Explain the dietary modifications - obesity, Explain the Dietary Modificati...

Explain the Dietary Modifications - Obesity? The dietary modifications serve as a guide for the obese to make healthy food choices. The first step towards prescribing a diet fo

Define cause of vitamin a deficiency - infections, Define cause of vitamin ...

Define cause of vitamin a deficiency - Infections? During acute infections, vitamin A intake in preschool children is reduced due to impaired appetite and impaired vitamin A ab

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