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.
Process of Respiration Respiratory and Circulator System Gaseous exchange that is intake of oxygen and output of carbon dioxide, takes place at the respiratory surface since
Q. Which are the three hormones that participate in the regulation of the renal function? Antidiuretic hormone or ADH or vasopressin, atrial natriuretic factor (or ANF) and ald
Choice of a prophylactic agent An effective prophylactic regimen should be directed against the most likely infecting organisms, but need not eradicate every potential pathogen
What are the consequences of iodine deficiency disorders? As discussed earlier under signs and symptoms, the consequences of IDD include: mental retardation, other defects in t
INSULIN Linear polymer of b-D-Glucose. Insulin is small-sized (25 - 35 residues) fructosan homopolysaccharide which is a reserve carbohydrate present in roots, tubers and
excretory product of marine teleost
- Oogenesis involves the formation of haploid cells from an original diploid cell, called a primary oocyte, through meiosis. - The female ovaries contain the primary oocyte. The
Question 1 Give the definition and describe the mechanism of Active transport. Passive transport with suitable examples Question 2 What are neurons? List out the
Why do we need a family of proteins for cell adhesion (what is the advantage of having a family of proteins?)
what microbe is the one that is shaped like a ball with spikes comming out
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