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

Explain tetanus and diphtheria, Tetanus and Diphtheria  Everyone who ha...

Tetanus and Diphtheria  Everyone who has had a primary series as a child should receive a tetanus-diphtheria toxoid (Td) booster injection once every 10 years. Before traveling

Dietetic foods for diabetes, Dietetic Foods for diabetes: With advances...

Dietetic Foods for diabetes: With advances in food technology, foods for special use by diabetics are now available in the global market, they are emerging in India also. These

In the phase when the cell is not dividing interphase, Q. In the phase when...

Q. In the phase when the cell is not dividing interphase is there activity within the cell nucleus? In the interphase there is intense metabolic activity in the cell nucleus th

Explain what is cyanosis and polycythemia, Explain what is Cyanosis and pol...

Explain what is Cyanosis and polycythemia? Cyanosis and Polycythemia: Central cyanosis involving the mucous membranes and trunk along with the lips and extremities in absence

How many types of gametes can be formed, How many different types of gamete...

How many different types of gametes can be formed by individuals of the following genotypes? What are they in each case a) AaBb b) AaBB c) AaBbCc d) AaBBCc e) AaBbcc f) AaBbCcDdEe

Zoology, why phylum protozoa is called protozoa?

why phylum protozoa is called protozoa?

Explain isolated chloroplast thylakoids, In an experiment, isolated chlorop...

In an experiment, isolated chloroplast thylakoids were incubated at pH 4.0 with ADP and inorganic phosphate (Pi) added to the medium and then transferred to a medium having pH 8.0.

What are hormones, What are hormones? Hormones are chemicals secreted b...

What are hormones? Hormones are chemicals secreted by the body to create changes in physical appearance, reproductive behavior, and emotions. Hormones are organic chemical m

Do plants present only sexual reproduction, Q. Do plants present only sexua...

Q. Do plants present only sexual reproduction? There are asexual forms of reproduction in plants few naturally detached pieces of root, leaves or limbs develop into another com

Hormones of pancreas, HORMONE S OF PANCREAS AND THEIR ROLE - (i) Glu...

HORMONE S OF PANCREAS AND THEIR ROLE - (i) Glucagon (Secreted by a-cells) It stimulates the liver to convert stored glycogen into glucose. Glucagon is controlled b

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