Important Points on Microbiology:Part---1

Important Points on Microbiology:Part---1

1) Cell theory was proposed by Robert Hooke in 1665.

2) Cells can be divided in to following two categories

Prokaryotes
Eukaryotes

3) Prokaryotes:
The prokaryotes are a group of organisms that lack a cell nucleus or any other membrane-bound organelles.
Ex.: Bacteria and Cyanobacteria

4) Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes.
Ex.: Animal cell, Plant Cell, Algae, Fungi

5) Based on chemical composition of cell wall, bacteria can be classified in to following two categories.
1) Gram positive bacteria.
2) Gram Negative Bacteria.

6) Are viruses considered either eukaryotes or prokaryotes?
Viruses are not comes under eukaryotes and prokaryotes. Viruses are acellular. It may be called as akaryotic.

7) Basic shapes of Bacteria:

Round shape --- called as Coccus.
Rod shape --- called as Bacillus.
Spiral shape --- called as Spirillum.

8) What is pleomorphic?
Some bacteria can later their shapes and occur in different shapes. It is called as pleomorphic.

9) Example for pleomorphic?
Rhizobium
Mycoplasma
Arthrobacter.


10) The first virus to be crystallized was
Tobacco mosaic virus (TMV) in 1935 by Wendell Meredith Stanley.


11) The five kingdom classification was proposed by
R.H.Whittaker in the year 1969.
12) The two components of the binomial name of microorganisms are
Genus and Species.

13) What is flagella?
Some bacteria have ability to move from one place to other by means of appendages called flagella.

14) Form of flagella:
Monotrichous: Single flagellum found on bacteria. Ex. Pseudomonas aeruginosa.
Amphitrichous: A flagellum found on each end of the cell. Ex: Aquaspirillum serpens
Lophotrichous: Multiple flagella at the end of the cells. Ex: pseudomonas fluorescens
Peritrichous : Flagella found on entire body of the cells. Ex: salmonella typhi

15) what is pili?
A hairlike appendages found on surface of many bacteria. It is called as Pili.
16) An alternative name for pili is Fimpriae.
17) What is difference between flagella and pili based on usage on bacteria?

Flagella used to move and Pili used to initially colonize host cells.

18) What is psychrophilic bacteria?
It is a type of bacteria that are capable of growth and reproduction in cold temperatures, ranging from −15°C to +10°C. Ex. Arthrobacter sp., Psychrobacter sp.

19) What is mesophilic bacteria?
It is a type of bacteria that grows best in moderate temperature, neither too hot nor too cold, typically between 25 and 40 °C. Ex. E.coli, Salmonella Sp, etc.

20) What is thermophilic bacteria?
It is a type of bacteria that are capable of growth and reproduction in high temperatures between 45 and 80 °C. Ex. Thermus aquaticus

21) What is Acidophilic bacteria?
Acidophilic bacteria are those that thrive under highly acidic conditions (usually at pH 2.0 or below). Ex. Thiobacillus acidophilus.

22) What is Alkaliphilic bacteria?
It is a type of bacteria that are capable of growth and reproduction in high pH between 9 and 11 Ex. Bacillus okhensis

23) What is Chemotaxis?
Movement of bacteria in response to chemicals is called Chemotaxis.

24) The Hereditary substance in all microorganisms is DNA.
25) Nomenclature was established by?
Carolus Linnaeus.