HI EVERYONE I AM IBRAHIM KHAN. TODAY  WE ARE GONNA LEARN ABOUT THE CHARACTERISTICS OF VIRUS .GUYS I AM SURE YOU ALL KNOW HOW MINIATURE BACTERIUM ARE.... BUTALL THESE  VIRUSES ARE EVEN TINY THAN A BACTERIUMVIRUSES ARE EXTREMELY SMALL SUBSTANCES MADE OF NUCLEIC ACIDS AND PROTEINS.THESE CREATURE CAN ONLY BE SEEN WITH A HELP OF ELECTRON MICROSCOPE.THEY TAKE OVER THE METABOLISM OF THEIR HOST CELL IN THEIR OWN FAVOUR  PRODUCING MORE VIRUSES AND USUALLY KILLING THE HOST CELLS.THEY DO NOT LIVE FREELY IN NATURE AND LIVE INSIDE OTHER CELLS. THESE VIRUSES ARE VERY SPECIFIC.THEY ONLY ATTACK A CERTAIN TYPE OF HOST.