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

Chemical properties of soil, CHEMICAL PROPERTIES OF SOIL Soil is a high...

CHEMICAL PROPERTIES OF SOIL Soil is a highly dynamic system which supports complex chemical reactions. In this heterogeneous systems, the soil solution acts as the medium for c

What are the presumed target substrates, What are some of the presumed targ...

What are some of the presumed target substrates for cyclin-dependent kinases?

Explain class bivalvia in animal kingdom, Explain Class Bivalvia in animal ...

Explain Class Bivalvia in animal kingdom? This name of this Class reflects the group's most distinguishing feature. Clams, oysters, scallops and mussels all have two shells tha

What do you mean by hemichordata, Q. What do you mean by Hemichordata ? ...

Q. What do you mean by Hemichordata ? Hemichordates re vermiform (worm-like) animals which have few characters like those of the chordates, hence the name hemichordata (hemi :

Learning objectives of gastrointestinal disease, Q. Learning objectives of ...

Q. Learning objectives of gastrointestinal disease? • explain the disease conditions, causes, complications of the disorders of the gastrointestinal tract, • discuss the ef

Define fat needs in nutrient requirement, Define Fat needs in Nutrient Requ...

Define Fat needs in Nutrient Requirement and Dietary Management? As we have learnt earlier on enteral and parenteral feedings; administration of lipids should be carried out ca

Phases of nurse-patient relationship, PHASES OF NURSE-PATIENT RELATIONSHIP:...

PHASES OF NURSE-PATIENT RELATIONSHIP: Kapoor, Bimla (1994) has listed four phases of  nurse patient relationship which are explained below while describing the phases she has

Pulmonary edema, Pulmonary edema occurs when movement of liquid from the bl...

Pulmonary edema occurs when movement of liquid from the blood to the interstitial space and/or into the alveoli exceeds the return of liquid to the blood and its drainage through t

Explain the bases, The bases in DNA have carbon-nitrogen ring structures; d...

The bases in DNA have carbon-nitrogen ring structures; due to the nitrogen atoms they are known as nitrogenous bases. There are two parts of ring structure. Adenine and guanine are

Rate related bundle branch block, Q. Rate Related Bundle Branch Block? ...

Q. Rate Related Bundle Branch Block? The term has often implied the absence of significant coronary or myocardial pathology. It cannot be judged without taking the total clinic

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