CBSE Class 9 Biology, 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.

•   These are prokaryotic, unicellular, autotrophic or heterotropic organisms.

•   These are unicellular and eukaryotic, autotrophic or heterotrophic organisms.

•   They are further classified as protistan algae, slimemoulds, and protozoa.

•   Multicellular and eukaryotic organisms having plant like and animal like features. They may be parasitic or saprophytic.

•   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.

•   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.