The very simple difference between Virus and Bacteria is that Virus is smaller than a bacteria WHILE a Bacteria is larger than a virus. The worthy thing to mention here is that bacteria is considered a fully functional microorganism while a virus lacks characteristics of a fully functional organism.
Organisms are classified into two major categories Eukaryotes and Prokaryotes. Eukaryotes are those organisms having the nucleus in their cells but Prokaryotes do not have a nucleus in their cells. According to biological researches, prokaryotes are classical organisms and came to existence before eukaryote. Bacteria is prokaryote while a virus cannot be yet considered a prokaryote or a eukaryote.
Difference between Virus and Bacteria in the column:
|1.||It is much smaller than bacteria, and its recorded size is 20-200 nm||It is larger than a virus and its recorded size is nearly 1000 nm.|
|2.||These are always infectious and are not human friendly.||These are not always infectious there are some bacteria that are human friendly and even help In digestion.|
|3.||Cannot be considered either prokaryote or eukaryote||There are both eukaryotic and prokaryotic bacteria.|
|4.||It can even infect bacteria||It cannot infect virus.|
|5.||It cannot be considered as a parasite.||It can be considered as a parasitic organism.|
|6.||It always requires a host cell for its replication/reproduction.||It does not always require a host cell for reproduction in fact It can reproduce on their own using the asexual method of reproduction.|
|7.||Antibiotics cannot kill viruses.||There is a wide range of antibiotics that kills bacteria.|
|8.||These are very simple in structure with having only DNA or RNA packaged inside a membranous or protein coat.||These have a complex structure including many cell organelles and DNA or RNA inside the nucleus or freely moving without a nucleus.|
|9.||Illnesses caused by this include Chickenpox, Influenza, Common cold, AIDS, SARS, MERS, Cholera, Plague, Hepatitis, Measles, Ebola, herpes, and rabies.||Illnesses include: Food poisoning, Meningitis, Ear infection, Pneumonia, Strep throat, and gonorrhea|
|10.||There is no virus in a human body if present then it could be an alarming situation.||There is a large number of bacteria inside the human body to more than the number of humans cells.|
|11.||Viral infections are always contagious.||Bacterial infections are not always contagious.|