Diversity in Living Organisms-Notes

Class IX Science
Notes for Diversity in Living Organisms
•   Biodiversity refers to variability.
•   The diverse forms of organism need classification.
•   The evolutionary history decides the phylogenetic classification.
•   H. Whittaker proposed the five kingdom system of classification
•   A distinct name is a need for identification.
•   Common names are unscientific.
•   Binomial nomenclature is scientific naming of organisms.
•   Taxonomic hierarchy is the framework of classification which helps in appropriate placing of organisms.
1. Monera
•   These are prokaryotic, unicellular, autotrophic or heterotropic organisms.
2. Protista
•   These are unicellular and eukaryotic, autotrophic or heterotrophic organisms.
•   They are further classified as protistan algae, slimemoulds, and protozoa.
3. Fungi
•   Multicellular and eukaryotic organisms having plant like and animal like features. They may be parasitic or saprophytic.
4. Plantae
•   These are multicellular, eukaryotic and autotrophic organisms. They are further classified.
•   Thallophyta – Thallus like body, mostly autotrophic and aquatic.
•   Bryophyta – Simple plants with no vascular system. They are amphibious.
•   Pteridophytes – They are land plants with true vascular system.
•   Gymnosperms – They are land plants bearing naked seeds.
•   Angiosperms – They are flowering plants with seeds covered by fruits.
5. Animalia
•   These are multicellular, eukaryotic and heterotrophic organisms. They are further classified.
•   Porifera – Pore bearing organisms.
•   Coelenterata – Organisms with hollow gut.
•   Platyhelminthes – unsegmented flat worms.
•   Nematoda – Unsegmented round worms.
•   Annelida – Metamerically segmented worms.
•   Arthropoda – These are animals with jointed appendages.
•   Mollusca – Soft bodied animals.
•   Echinodermata – Spiny skinned animals.
•   Chordata – Dorsal nerve cord,
    notochord and gill slits.