* virus, viroids and lichen are acellular organism which have no place in five kingdom classification.
* VIRUS- viruses are non-cellular organism. they have inert crystalline structure outside the living body.
-when they invert living cell they take over the machinery of the host cell to replicate themselves and kill the host cell.
-D.J.IVANOWSKY(1892) named virus means poisonous fluid.
-M.W.BEIJERINEK(1898) discovered TMV(tobacco mosaic virus)
-W.M.STANLEY (1935) showed that virus could be crystallised and crystals consist largely of proteins.
-viruses are obligate parasites.
-it contain genetic material DNA or RNA.
-Bacteriophages or bacterial viruses are usually have double strand DNA.
-the protein coat of virus of capsid, made up of small subunits called capsomeres protect the nucleic acid.
-these capsomere are arranged in helical or polyhedral geometric form.
-disease caused by virus are AIDS, mumps,small pox etc.
BACTERIOPHAGE
TMV
- it lacked the protein coat.
- RNA of viroid had low molecular weight.
* LICHENS - association of algae and fungus is calledlichen.
- algal component is called phycobiont and fungal component as mycobiont.
- algae prepare food for fungus and fungus provide shelter and absorb mineral and water from soil.
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* VIRUS- viruses are non-cellular organism. they have inert crystalline structure outside the living body.
-when they invert living cell they take over the machinery of the host cell to replicate themselves and kill the host cell.
-D.J.IVANOWSKY(1892) named virus means poisonous fluid.
-M.W.BEIJERINEK(1898) discovered TMV(tobacco mosaic virus)
-W.M.STANLEY (1935) showed that virus could be crystallised and crystals consist largely of proteins.
-viruses are obligate parasites.
-it contain genetic material DNA or RNA.
-Bacteriophages or bacterial viruses are usually have double strand DNA.
-the protein coat of virus of capsid, made up of small subunits called capsomeres protect the nucleic acid.
-these capsomere are arranged in helical or polyhedral geometric form.
-disease caused by virus are AIDS, mumps,small pox etc.
*VIROIDS- T.O.DIENER discovered a new infectious agent smaller than virus
- it was a free RNA- it lacked the protein coat.
- RNA of viroid had low molecular weight.
- algal component is called phycobiont and fungal component as mycobiont.
- algae prepare food for fungus and fungus provide shelter and absorb mineral and water from soil.
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