Viruses as living: Have genetic material i.e either #"DNA"# or #"RNA"#. Can undergo mutation. Show irritability. Are capable to reproduce and hence can increase their number. React to heat, chemicals and radiations. Are resistant to antibiotics.
The overall shape of virus varies in different groups of virus. Most of animal viruses are spherical shape, Pox virus is rectangular shape, TMV is rod shape, Poliovirus is bullet shape etc Some virus are irregular and pleomorphic in shape. 3. Symmetry:
Have genetic material i.e either DNA or RNA. Can undergo mutation. Show irritability. Are capable to reproduce and hence can increase their number. React to heat, chemicals and radiations. Are resistant to antibiotics. Can be crystallized. Are inert outside the host. Lack cell membrane and cell wall.
Viral genome or nucleic acid contains either DNA or RNA but not both. The genome can exist as single piece or segmented. Eg, Influenza virus contains 8 segments of ss RNA genome. The genome may be linear or circular. Most virus possess linear genome except Papova virus which contains circular ss DNA.
Viruses are infectious agents with both living and nonliving characteristics. Living characteristics of viruses include the ability to reproduce – but only in living host cells – and the ability to mutate.
Which properties of life are possessed by viruses and green turtles? a clear orderly arrangement and ability to reproduce.
So were they ever alive? Most biologists say no. Viruses are not made out of cells, they can't keep themselves in a stable state, they don't grow, and they can't make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.
Are they alive? One of the fundamental hallmarks of life is the ability to reproduce. Whether viruses have this ability is key to a debate over their status as living things.
When brought together in a zoo, two species are capable of mating and producing fertile offspring. Why may they still be considered two distinct species? Zoos are not natural environments. Under the biological species concept, what criterion is used to assign populations of organisms to the same biological species?
CellsCells are an organism's basic unit of structure and function. The cell is the lowest level of structure that is capable of performing all the activities of life.
The characteristics that viruses have common with living organisms are reproduction and heredity. They can only reproduce inside the host cell and they do have DNA or RNA.
Viruses are not living things. Viruses are complicated assemblies of molecules, including proteins, nucleic acids, lipids, and carbohydrates, but on their own they can do nothing until they enter a living cell. Without cells, viruses would not be able to multiply. Therefore, viruses are not living things.
Nevertheless, most evolutionary biologists hold that because viruses are not alive, they are unworthy of serious consideration when trying to understand evolution. They also look on viruses as coming from host genes that somehow escaped the host and acquired a protein coat.
Viruses do not have cells. They have a protein coat that protects their genetic material (either DNA or RNA). But they do not have a cell membrane or other organelles (for example, ribosomes or mitochondria) that cells have. Living things reproduce.
Viruses possess genetic material (DNA or RNA) and evolve by natural selection. However, viruses do not have a cellular structure, do not maintain homeostasis, and cannot reproduce on their own. Because they lack the ability to maintain homeostasis and lack cellular organization, viruses are not considered cells.
CharacteristicsNon living structures.Non-cellular.Contain a protein coat called the capsid.Have a nucleic acid core containing DNA or RNA (one or the other - not both)Capable of reproducing only when inside a HOST cell.