SUMMARY
As you have learned, there are many important differences between viruses and bacteria. Viruses are nonliving entities that must infect a cell in order to make additional copies of themselves. The ability of a virus to infect particular cell types is governed by interactions between the viral capsid (or spike proteins projecting from the capsid) and receptor molecules on the target cell. The replication strategy of the virus depends on the type of genetic material that is housed within the capsid.

Bacteria, unlike viruses, are true cellular organisms. Bacteria possess structures that allow them to attach to surfaces, move throughout the environment, and transfer genetic material among bacterial species. While some bacteria are able to cause disease, most bacteria are beneficial and play critical roles in the recycling of nutrients, nitrogen fixation, and the removal of pollutants from our environment (bioremediation).

Activity
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