What are the differences between bacteria and viruses?

Question

Accepted Answer

Basis of differentiation

Bacteria

Viruses

Definition

Are free-living cells that can live inside or outside a body

Are non-living collection of molecules that need a host to survive

Number of cells

One cell (unicellular)

No cells (acellular)

Size

Large, 900 - 1000 nm

Smaller 30-500 nm

Visibility

Visible under Light Microscope

Visible only under Electron Microscope

Cell wall

Has a cell wall composed of Peptidoglycan or Lipopolysaccharide

Does not have a cell wall, instead the genetic material is enveloped by a protein coat known as a capsid

Cellular machinery

Possesses a cellular machinery

Lack cellular machinery

Characteristics of DNA and RNA

DNA and RNA float freely in cytoplasm

DNA or RNA are enclosed inside a coat of protein known as capsid

Ribosomes

Present

Absent

nucleus

no

Ability to reproduce

Able to reproduce by itself

Need a living cell to reproduce

Mode of reproduction

Asexually by binary fission, which is a form of asexual reproduction

Invade a cell host and insert their genome in the host genome, making multiple copies of the viral DNA/RNA, thus destroying the host cell and releasing new viruses

Mode & Type of infection

Opportunistic and localized infection – Bacteria typically infect the host when the opportunity arises and the infection is confined to one part of the body

Systemic infection – After infecting a host cell viruses multiply by the thousands, leaving the host cell and spreading the infection throughout the body

Common diseases caused

Tetanus, food poisoning, gastritis and ulcers, meningitis, pneumonia, and tuberculosis

Influenza, AIDS, common cold, measles, chickenpox, polio and COVID-19

Duration of illness

Longer than 10 days

About 2 to 10 days

Treatment

Antibiotics are an effective treatment

Do not respond to antibiotics. Antiviral drugs and vaccines prevent the spread of viruses and slow reproduction

Virulence

yes

Fever

Bacterial infection typically causes a fever

Viral infection may or may not cause a fever

Examples

Staphylococcus aureus, Vibrio cholerae,

HIV, Hepatitis A virus, RhinoVirus,

Basis of differentiation	Bacteria	Viruses
Definition	Are free-living cells that can live inside or outside a body	Are non-living collection of molecules that need a host to survive
Number of cells	One cell (unicellular)	No cells (acellular)
Size	Large, 900 - 1000 nm	Smaller 30-500 nm
Visibility	Visible under Light Microscope	Visible only under Electron Microscope
Cell wall	Has a cell wall composed of Peptidoglycan or Lipopolysaccharide	Does not have a cell wall, instead the genetic material is enveloped by a protein coat known as a capsid
Cellular machinery	Possesses a cellular machinery	Lack cellular machinery
Characteristics of DNA and RNA	DNA and RNA float freely in cytoplasm	DNA or RNA are enclosed inside a coat of protein known as capsid
Ribosomes	Present	Absent
nucleus	no	no
Ability to reproduce	Able to reproduce by itself	Need a living cell to reproduce
Mode of reproduction	Asexually by binary fission, which is a form of asexual reproduction	Invade a cell host and insert their genome in the host genome, making multiple copies of the viral DNA/RNA, thus destroying the host cell and releasing new viruses
Mode & Type of infection	Opportunistic and localized infection – Bacteria typically infect the host when the opportunity arises and the infection is confined to one part of the body	Systemic infection – After infecting a host cell viruses multiply by the thousands, leaving the host cell and spreading the infection throughout the body
Common diseases caused	Tetanus, food poisoning, gastritis and ulcers, meningitis, pneumonia, and tuberculosis	Influenza, AIDS, common cold, measles, chickenpox, polio and COVID-19
Duration of illness	Longer than 10 days	About 2 to 10 days
Treatment	Antibiotics are an effective treatment	Do not respond to antibiotics. Antiviral drugs and vaccines prevent the spread of viruses and slow reproduction
Virulence	yes	yes
Fever	Bacterial infection typically causes a fever	Viral infection may or may not cause a fever
Examples	Staphylococcus aureus, Vibrio cholerae,	HIV, Hepatitis A virus, RhinoVirus,

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