Diffrence between bacteria & virus
BACTERIA
Bacteria are single celled microbes. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Instead their control centre containing the genetic information is contained in a single loop of DNA. Some bacteria have an extra circle of genetic material called a plasmid. The plasmid often contains genes that give the bacterium some advantage over other bacteria. For example it may contain a gene that makes the bacterium resistant to a certain antibiotic.
( note :- Bacteria are classified into five groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains or clusters).
Viruses are the smallest of all the microbes. They are said to be so small that 500 million rhinoviruses (which cause the common cold) could fit on to the head of a pin. They are unique because they are only alive and able to multiply inside the cells of other living things. The cell they multiply in is called the host cell.
A virus is made up of a core of genetic material, either DNA or RNA, surrounded by a protective coat called a capsid which is made up of protein. Sometimes the capsid is surrounded by an additional spikey coat called the envelope. Viruses are capable of latching onto host cells and getting inside them.
H3N2 influenza virus particles, coloured transmission electron micrograph (TEM). Each virus consists of a nucleocapsid (protein coat) that surrounds a core of RNA (ribonucleic acid) genetic material. Surrounding the nucleocapsid is a lipid envelope that contains the glycoprotein spikes haemagglutinin (H) and neuraminidase (N). These viruses were part of the Hong Kong Flu pandemic of 1968-1969 that killed approximately one million people worldwide. H3N2 viruses are able to infect birds and mammals as well as humans. They often cause more severe infections in the young and elderly than other flu strains and can lead to increases in hospitalisations and deaths.
Viruses only exist to make more viruses. The virus particle attaches to the host cell before penetrating it. The virus then uses the host cell’s machinery to replicate its own genetic material. Once replication has been completed the virus particles leave the host by either budding or bursting out of the cell (lysis).
1. Classification of bacteria & virus
|
|
Bacteria |
Virus |
|
Cellular
organisation |
Present |
Absent |
|
Growth
in inanimate media |
Yes |
No |
|
Binary
fission |
Yes |
No |
|
Both
DNA and RNA |
Yes |
Only
1 nucleic Acid Present |
|
Ribosomes |
Present |
Absent |
|
Sensitivity
and antibiotic |
Yes |
No |
|
Genetic
iformatio system |
Present |
Absent |
|
Size |
>300nm |
<300nm |
|
Filterable |
Yes |
No |
|
Seen
by microscope ordinary |
Yes |
No |
|
Presence
of ATP |
Yes |
No |
|
Oncogenic
character |
No |
Yes |
|
Staining
method of identificaton |
Yes |
No |
|
Incubation
period |
Small
range |
Wide
range |
