Limitations of five-kingdom classification, Biology

Assignment Help:

Limitations of Five-Kingdom Classification

As already pointed out, each system of classification has its own limitations. The two-kingdom system has outlived its usefulness as it could not do justice to forms like Euglena and Volvox. The three-kingdom classification failed to accommodate properly prokaryotic forms. The limitation of the four-kingdom classification was that despite creation of kingdom Monera it failed to account for the intergradations between Protista and Animalia.

The present five kingdom system is also not the final solution to the problems of taxonomy. In this system too we have many weaknesses despite the acceptance of this system by most biologists. The exclusion of Protozoa from the animal kingdom, in this system concerns many zoologists. Protozoa share many characteristics with Metazoan animals. Most ingest their food; many have specialised organelles and advanced locomotory systems; many reproduce sexually and some flagellate protozoa are colonial with division of labour among cell types. Indeed, there is little doubt that metazoan animals evolved from one or more protozoans groups. Thus zoologists though accepting that are eukaryotic protists and not animals according to the five kingdom classification, still continue to claim Protozoa as their own. This system is also not able to show clearly the inter-relationships of various groups in all instances. Even now many phyla contain forms whose relationships are not clearly understood. among nonchordates the grouping collectively called Minor phyla has unsolved problem of phylogenetic placement. Recently, many biologists have also tried to split the kingdom Monera into two: (i) Eubacteria and (ii) Archaebacteria, leading thus to the proposal of six kingdoms.

In fact, during the past twenty years various revisions in the classification system have been discussed with the number of kingdoms ranging from 3-13. Biologists generally follow the five-kingdom-classification despite its inadequecies because it appears to be the most acceptable system today and indeed the most convenient one available.


Related Discussions:- Limitations of five-kingdom classification

Problem with role of lymphatic system, Normal 0 false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Write briefly about the bacterial growth curve, Question 1 Write briefly a...

Question 1 Write briefly about the Bacterial growth curve Question 2 Define Virus. List out the general properties and classification of virus Question 3 What is Immunog

State the enzymes utilization in brewing industry, Enzymes utilization in B...

Enzymes utilization in Brewing Industry Here, the main starting material is malt, produced by allowing barley seeds to germinate under moist conditions. The reserve starch is b

Explain the pre pregnancy weight and foetal outcome, Explain the Pre Pregna...

Explain the Pre Pregnancy Weight and Foetal Outcome? Several studies from around the world from developing and developed countries have demonstrated an association between pre-

What are alternative medicines, Question 1: Differentiate between Tradi...

Question 1: Differentiate between Traditional, complementary and alternative medicines. Cite examples for each type. Definition of Traditional, alternative medicines and

Define clinical progress for treatment for pem, Define Clinical progress fo...

Define Clinical progress for treatment for pem? Normally, clinical improvement is evident within a week with the disappearance of oedema, The appetite improves almost dramatica

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

Interaction of pyridoxine with ascorbic acid and leucine, Define Interactio...

Define Interaction of pyridoxine with Ascorbic acid and Leucine? Ascorbic acid: Vitamin B 6 metabolism increases with. Higher levels of vitamin C intake. Whole blood a

Describe the need for harmonization in clinical trials, Question 1: Des...

Question 1: Describe the need for Harmonization in clinical trials? Brief on the Revised ICH terms of reference and explain the structure of ICH? Need for Harmonization i

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