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

Musculoskeletal system, MUSCULOSKELETAL SYSTEM: Disease of  the skin  ...

MUSCULOSKELETAL SYSTEM: Disease of  the skin  and musculoskeletal  system occur commonly  in  early age group. There are  not many  statistics  to prove the exact frequency of

Why do fats have thermal isolation properties, Why do fats have thermal iso...

Why do fats have thermal isolation properties? Triglycerides are weak heat conductors and in addition they form thick layers of fat tissue when accumulated by the organism. Tha

Describe the effects of the failure of the pancreas, (a) Name the condition...

(a) Name the condition and (b) describe the effects of the failure of the pancreas to produce sufficient-insulin. (c) How is this condition treated? .

What is food pyramid, Food Pyramid The diabetes food pyramid divides fo...

Food Pyramid The diabetes food pyramid divides food into six groups. These groups vary with each other on the basis of size occupied in the pyramid. The largest i.e. grains, br

Diffusion, applications of diffusion

applications of diffusion

Difference between algae and protozoans, Q. What is the fundamental differe...

Q. What is the fundamental difference between algae and protozoans? The basic difference between algae and protozoans is the fact that algae are photosynthetic autotrophs while

Which glands is affected by the hormones, Which pair of glands is affected ...

Which pair of glands is affected by the hormones from the posterior pituitary? A) thyroid, ovaries B) adrenal cortex, liver C) testes, mammary glands D) kidneys, uterus

Marking regulations of honey, Q. Marking regulations of honey? The mar...

Q. Marking regulations of honey? The marking regulations indicate that each container of honey shall be suitably marked so as to give suitable information as follows: a) N

How are the male gametophytes formed in angiosperms, Q. How are the male ga...

Q. How are the male gametes and the male gametophytes formed in angiosperms? In the anthers of every stamen there are pollen sacs. Inside the pollen sacs there are microspore m

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