Key Takeaways

KEY TAKEAWAYS

• Viruses are not technically forms of life because they lack the recognized features that identify life forms. • Viruses are obligate parasites and cannot replicate without a host cell. • Viruses have been studied and treated for thousands of years with the most information gotten in the last hundred years about these particles. • Viruses have three distinct shapes in general but there are some variations in certain types. • There are different theories of virus evolution, particularly as they relate to the origin of viruses themselves. • The viruses have several different classifications based on the type of nucleic acid inside the cell. • The viral life cycle proceeds the same for most infections but some will have a less typical lysogenic cycle that doesn’t immediately kill the cell. • Bacteriophage infections indirectly affect animals and humans because some will cause the bacteria infected to be much more virulent in general.