A virus is a non-celular parasite that only can reproduce
by invading the cell of other living things
The structure of viruses
Viruses consist of a stand of nucleic acid, (genetic material which can be
DNA or RNA) surrounded by a protective protein coat calleda capsid.
Some viruses, such as influenza, have a further membrane envelope of
lipid, surrounding the protein. Other viruses also have a tail
Life processes of
viruses
As they do not feed, they are considered obligate parasites and, in order to
reproduce, they insert their genetic material in the cells of living organisms.
Viruses only have the life process of
reproduction.
Reproduction of
viruses
The virus attaches itself to the cell membrane. The whole
virus or just its genetic material is injected into the cell.
The host cell follows the instructions from the genetic material of the virus
and replicates the nucleic acids and produces the capsid and tail proteins.
All of the components are put together and a new virus is created and
released. This can destroy the host cell.