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.
Promoters The promoter region contains the DNA sequences that allow the formation of the transcription initiation complex that give the specificity of expression. Promoters are
What do you understand by Dimorphic nuclei? Organization of the nuclear material typical of ciliates. There is always a single small micronucleus and either one large or many m
Q. What is Coping? Coping refers to a person's patterns of response to stress. Coping is the process of managing circumstances, making effort to solve personal and interpersona
Q. What is the typical feature of the epithelia? How different is it from the connective tissue? The typical feature of the epithelium is the almost absence or absence of space
what is r and k selection
Suppose that a portion of double-stranded DNA in the middle of a large gene is being transcribed by an RNA polymerase. As the polymerase moves through the sequence of six bases sho
Define Some Food Related Problems in parkinson's disease? As the disease progresses some food related difficulties appear. These are: 1. Difficulty in food preparation
Define Colorimetric Method - 2, 4 Dinitrophenylhydrazine Method? We shall use this method in estimating vitamin C in a given sample in the laboratory. Here, let us look at the
Write short note on glycogen storage diseases. Glycogen storage diseases are caused by genetic defects that result in deficiencies in certain enzymes of glycogen metabolism.
notochotr is absent in the group ...........
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