Table of contents | |
What is Biological Classification? | |
1. Kingdom Monera | |
2. Kingdom Protista | |
3. Kingdom Fungi | |
4. Kingdom Plantae | |
5. Kingdom Animalia | |
Viruses, Viriods, Prions and Lichens |
The process of grouping together various organisms according to their similarities, dissimilarities and phylogenetic descent is known as biological classification.
Five Kingdom Classification by Whittaker
- Previous Classifications: Earlier systems grouped diverse organisms, such as bacteria, algae, fungi, and various plants, primarily based on the presence of a cell wall.
- Unified Characteristics: The unifying feature of the earlier classifications was the cell wall, leading to the grouping of prokaryotic and eukaryotic organisms together despite their differences.
- Kingdom Protista has brought together Chlamydomonas, Chlorella (earlier placed in Algae within Plants and both having cell walls) with Paramoecium and Amoeba (which were earlier placed in the animal kingdom which lack cell wall). It has put together organisms which, in earlier classifications, were placed in different kingdoms
- Over time, an attempt has been made to evolve a classification system which reflects not only the morphological, physiological and reproductive similarities, but is also phylogenetic, i.e., is based on evolutionary relationships.
Kingdom Monera: Bacteria Cell Structure
Eubacteria- These are true bacteria and have a rigid cell wall and motile organisms have flagella.
A. Photosynthetic Autotrophs
They include Cyanobacteria (Blue-green Algae). They have chlorophylls and carotenoids. They are unicellular, filamentous or colonial and the body is covered by a mucilaginous sheath. Nostoc and Anabaena have heterocysts, where they can fix atmospheric nitrogen.
B. Chemosynthetic Autotrophs
They play an important role in recycling nutrients. They get the required energy for ATP generation from the oxidation of various inorganic substances such as ammonia, nitrates and nitrites.
C. Heterotrophic
There is a wide variety of heterotrophic bacteria. They act as a decomposer. They are used for various purposes such as nitrogen-fixing, curd and antibiotics production. Many bacteria are pathogen causing various diseases of plants and animals, e.g. citrus canker, tetanus, typhoid, cholera.
Bacteria Reproduction
Kingdom Protista: Eukaryotes
Diversity of Protists
(i) Chrysophytes
(ii) Dinoflagellates
(iii) Euglenoids
(iv) Slime moulds
(v) Protozoans
Some Important Fungi
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1. What are the main characteristics of organisms in the Kingdom Monera? |
2. How do organisms in the Kingdom Protista differ from those in the other kingdoms? |
3. What role do fungi play in the ecosystem? |
4. What are the key differences between the Kingdom Plantae and the Kingdom Animalia? |
5. What are lichens, and why are they not classified in Whittaker's Five-Kingdom system? |
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