Virus
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A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria a
Structure of icosahedral adenovirus; electron micrograph with an illustration to show shape
Structure of chickenpox virus. They have a lipid envelope.
Transmission electron microscope image of a recreated 1918 influenza virus
Two rotaviruses: the one on the right is coated with antibodies that prevent its attachment to cells and infecting them.
Life
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Life is the capacity in matter, formed of one or more units called cells, for processes such as cell signaling, homeostasis, metabolism, cell growth, adaptation, response to stimuli, and reproduction.
Virus
…natural selection, although they lack some key characteristics, such as cell structure, that are generally considered necessary criteria for defining life. Because they possess some but not all such qualities, viruses have been described as "organisms at the edge of life" and as replicators. Viruses spread…
Coral reef... South end of my area
Animal corpses, like this African buffalo, are recycled by the ecosystem, providing energy and nutrients for living organisms.
Adenoviruses as seen under an electron microscope
Cyanobacteria dramatically changed the composition of life forms on Earth by leading to the near-extinction of oxygen-intolerant organisms