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

What are the major characteristics of the bryophytes, Q. What are the major...

Q. What are the major characteristics of the bryophytes? Bryophytes are nonvascular plants that is they do not have conductive tissues and they perform transport of nutrients a

Uses of urine, Uses of Urine Urine is natural, easily available, harmle...

Uses of Urine Urine is natural, easily available, harmless, beneficial compound, which offers protection against a number of diseases. Now a day's urine after distillation from

Topical route for injection, Topical Route The medication in topical r...

Topical Route The medication in topical route is administered through ear, nose and eye. Drops are instilled into the nose, ear and eyes of the child in much the same way

Explain the activity of decomposers, Why are producers the first trophic le...

Why are producers the first trophic level to advantage from the activity of decomposers? Decomposers return nutrients in dead tissues and wastes to the soil or water; producers

Female reproductive system - uterus (womb), UTERUS (WOMB) - Large, p...

UTERUS (WOMB) - Large, pyriform, highly elastic. Development of embryo takes place in it. It is located above and behind the urinnary bladder. Attached to body wall by me

Methods of solid waste disposal, Commonly adapted different disposal method...

Commonly adapted different disposal methods by the municipal corporations are: (a)   Open dumping (b)   Land filling (c)    Sanitary land filling pyrolysis (d)   Incine

Inversion, Inversion We know that atmosphere is heated from below and w...

Inversion We know that atmosphere is heated from below and warm air rises, but air can be prevented from rising by a condition known as inversion. An inversion refers to a situ

Growth curve, typical growth curve in plants

typical growth curve in plants

using a two-sample t-test , After stinging its victim, the honeybee leaves...

After stinging its victim, the honeybee leaves behind the barbed stinger, poison sac, and muscles that continue to pump venom into the wound. A study compared two methods of removi

What does the formula dpd = sf - tp mean, What does the formula DPD = SF - ...

What does the formula DPD = SF - TP mean? DPD is the abbreviation of diffusion pressure shortage, SF (suction force) is the vacuolar osmotic pressure and TP is the turgor press

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