4. Diversity In Living Organism
Kingdom : Protista (Gk. Protistos-First of all)
Kingdom : Protista (Gk. Protistos-First of all) -
Kingdom Protista includes unicellular eukaryotic organisms. They are characterized by the following :
Protists are mostly aquatic and live wherever there is water.
The cell structure is typically eukaryotic. The protoplasm is surrounded by a distinct plasma membrane. In addition, some protists have an outer covering of pellicle, cuticle, shell or cellulose wall.
The genetic material is the linear, double-stranded, helical DNA, complexed with proteins, organized into dinstinct chromosomes. The chromosomes are enclosed by nuclear envelope. Nucleolus is present.
The cytoplasm contains memberane bound organelles such as mitochondria, plastids, Golgi bodies, endoplasmic reticulum, ribosome, etc.
Their mode of nutrition can be autotrophic or heterotrophic.
Motile protists move from one place to another with the help of pseudopodia, flagella or cilia.
Unicellular protists have been broadly divided into three major groups.
The protistan algae – eg., euglena, diatoms
Protozoan protists – amoeba paramecium