Viruses and viroids
Viruses Non living :- No components of cell No cell membrane Inert No metabolism No reproduction on its own Living :- Inert only outside a living host Possess genetic material (DNA/RNA ) They can reproduce / mutate when inside a living host Viruses Acellular Extremely small "Virus" term is given by ivanowsky Inert outside a host Obligate parasite They are those parasites that cannot complete its life cycle without exploiting a suitable host Structure : It is a nucleoprotein It contains a protein, genetic material in the form of RNA/DNA It has a protein coat :-capsid ensures protection of nucleic acid Capsid contains helical arrangement of capsomeres Plant viruses :- single strand of RNA Animal viruses :- double strand of RNA/DNA Bacterial viruses :- Bacteriophages (double strand of DNA ) Diseases :- AIDS , Small pox , Mumps , Influenza, Dwarfing in plants, Mosai...