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

Nutrient elements of plants, Nutrient Elements of Plants Let us first ...

Nutrient Elements of Plants Let us first find out the chemical composition of plants and see which element nature has selected to support their healthy growth. Only then we wi

Coevolution of plant-herbivores, There has been a perfect coevolution betwe...

There has been a perfect coevolution between plants and herbivorous animals. This has often developed into a mutually beneficial relationship. Whereas the plants have proved to be

Pumps, The pumps The blood from the operating field is sucked with t...

The pumps The blood from the operating field is sucked with the help of the cardiotomy sucker and pump, which is filtered to remove all particulate matter and then pass

Genetics and molecular biology into the darwinism, How does the synthetic t...

How does the synthetic theory of evolution incorporate knowledge from Genetics and Molecular Biology into the darwinism? Today it is known as that variation of inherited charac

Fermentation, outline the process of yeast fermentation stating all enzymes...

outline the process of yeast fermentation stating all enzymes involved

Best relates the severity and frequency of natural events, In general, whic...

In general, which of the following best relates the severity and frequency of natural events, such as storms or droughts? A) Nothing is known about this relationship. B) The severi

What happens within the cell in the first interface period, What are the ev...

What are the events that mark the beginning and the end of the first interphase period? What happens within the cell in this period? The first interphase period is the G1. It s

Interaction of insect hormones, Interaction of insect hormones in the proce...

Interaction of insect hormones in the process of metamorphosis The organs and the hormones usually included in metamorphosis of insects. This is since despite the fact that t

Mechanism of enzyme action, Mechanism  of Enzyme Action  The action of...

Mechanism  of Enzyme Action  The action of enzymes is to lower  the activation energy  or threshold  of their substrates which. Therefore  become  activated and   react  with

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