Characteristics of metazoa, Biology

Assignment Help:

Characteristics of Metazoa

The unicellular protozoans are highly versatile and successful organisms that show remarkable organization and division of labour within the confines of the single cell. This diversity is achieved by varying the structure of their organelles at the sub-cellular level. The Metazoa or the multicellular animals have achieved their structural diversity by varying their cells that have become specialized to perform different functions. These cells are normally incapable of independent existence. Let us list out some of the features that characterize metazoans.

1. Members of Metazoa possess a complex multicellular structural organization which may include the presence of tissues, organs and organ systems.

2. In the life history of metazoans, typically a fertilized egg passes through a blastula stage in the course of its early embryonic development before changing into an adult.

3. Since metazoans are multicellular they are relatively larger in size than unicellular protozoans. Naturally, their nutritional requirements are more and they have to search for food. Consequently, locomotion in metazoans is highly developed and for this purpose they have evolved contractile muscular elements and nervous structures.

 4. The ability for locomotion has influenced the shape of the metazoan animals which in turn has conferred specific types of symmetries to metazoan groups.

5. Most of the metazoans show differentiation of the anterior end or head (cephalization); associated with cephalisation, there is the centralization of the nervous system in the head region. Although all metazoans share some characteristic features, their body plans differ in symmetry, internal organization, developmental patterns and modes of formation of, body cavity. These differences provide us a means of grouping them or organising them into different phyla. Let s discuss these features one by 'one.


Related Discussions:- Characteristics of metazoa

The complex nature of earthquake ground motion, In fact a real earthquake g...

In fact a real earthquake ground motion at a particular site is much more complicated that than the simple waveform depicted. It would be beneficial if we make comparison between t

Nervous system, Nervou s System It is controling system of body. ...

Nervou s System It is controling system of body. Ectodermal in origin. This system is made up of nervous tissue. Nervous tissue is made up of neuron & neuroglial

Describe the basic function of erythrocytes, Q. What are the other names by...

Q. What are the other names by which erythrocytes are known? What is the function of these cells? Erythrocytes are also known as red blood cells (RBCs) or red corpuscles Red bl

What is the production of the rna, Q. What is the production of the RNA cal...

Q. What is the production of the RNA called and what is the enzyme that catalyzes the procedure? The making of the RNA from information contained in the DNA is called transcrip

What is mutualism, What is mutualism? Mutualism is the ecological inte...

What is mutualism? Mutualism is the ecological interaction in which both participants advantage and that is obligatory for their survival. Mutualism is a harmonious (positive)

Indication in circulatory assist devices, Indication :  IABP is commonly u...

Indication :  IABP is commonly used to supporting failing left ventricle after open-I1ca1-t surgery or in cardiogenic shock after myocardial infarction. It is at times used in uns

Explain the severe burns - clinical therapeutic nutrition, Explain the Seve...

Explain the Severe Burns - Clinical Therapeutic Nutrition? Severe, life-threatening bums require immediate care. Dehydration is treated with large amounts of fluids given intra

Types of mechanism - stress condition, Types of Mechanism - Stress Conditio...

Types of Mechanism - Stress Condition Plants have evolved a variety of mechanisms to withstand stress conditions. In many cases we can precisely define the way plants enable t

Define bitot''s spots - micronutrient deficiencies, Define Bitot's Spots - ...

Define Bitot's Spots - micronutrient deficiencies? As the deficiency progresses, dirty white, foamy and raised spots are formed on the surface of the conjunctiva, generally on

Alcohol related emergencies, Alcohol Related Emergencies: Alcohol is o...

Alcohol Related Emergencies: Alcohol is one of  the most serious health problems. Alcoholism is defined as a primary or chronic disease with genetic, psychological and environ

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