1. BIOLOGICAL CLASSIFICATION
- Aristotle was the earliest to attempt a more scientific
basis for classification of organisms.
- He classified plants into trees, shrubs & herbs and
animals into two groups, those which had red blood and
those that did not.
- In Linnaeus' time Two Kingdom classification (Kingdom
Plantae & Kingdom Animalia) was developed.
Drawbacks of 2-kingdom classification
Prokaryotes (Bacteria, cyanobacteria) and eukaryotes
(fungi, mosses, ferns, gymnosperms and angiosperms)
were included under ‘Plants’. It is based on the presence
of cell wall. But prokaryotes and eukaryotes are widely
differed in other characteristics.
It included the unicellular and the multicellular organisms
in same group. E.g. Chlamydomonas and Spirogyra were
placed under algae.
It did not differentiate between the heterotrophic fungi
and the autotrophic green plants. Fungi have chitinous
cell wall while the green plants have cellulosic cell wall.
Five Kingdom Classification
- It is proposed by R.H. Whittaker (1969).
- It includes Monera, Protista, Fungi, Plantae & Animalia.
- This classification is based on cell structure, thallus
organisation, mode of nutrition, reproduction and
Characteristics of the five kingdoms
Nuclear membrane Absent
Mode of nutrition
Present in some
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