Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Self- vs. Cross-Pollination A major advantage of self-pollination is its certainty. Continued self-pollination over many generations, however, results in weaker progeny. This
What are the female pronucleus and the male pronucleus? The female pronucleus is the proper haploid nucleus of the egg cell. Male pronucleus is the haploid nucleus of the sperm
Implantation - Pre-Embryonic Development After entering the uterus and formation of ICM, the blastocyst starts to embed in the endometrium of the uterine wall. By one week aft
Q. Which kind of polarity do fat-soluble and water-soluble substances respectively have? Ans. Water-soluble substances are behave as polar molecules, i.e., they have e
What are epithelial tissues? What are their general function and how is that function associated to the features of the tissue? Epithelial tissues, also known as epithelia, are
The major hazards encountered in the biological lab work are diseases like infections and allergies which are caused by handling live animals. dissections, plant and animal tissues
WHAT IS PANDA BAO BAOLOGY.?
Biota of Estuaries The estuarine community is a mixture of three components: Marine Fresh water and Brackish water but overall estuarine div
feeding mechanism of man
State the similarity between Shigella and Salmonella There are many points of similarity between Shigella and Salmonella. They dwell primarily in the gastrointestinal tract, wi
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd