Question

How are bacteria classified on the basis of number and distribution of flagella?

Answer 1

Hint: Flagella are the small outgrowths that are present on the membrane. They are hair like structures. Flagella are long that helps in cell movement. Flagella are found both in prokaryotes that are monerans. Monera is the kingdom of bacteria and also present in eukaryotes.

Complete answer:
- Monerans are the first kingdom in the five kingdom classification system. Bacteria are the only members of the kingdom Monera.
- They are classified on different basis as on their shape they are vibrio, spirillum, bacillus and coccus.
- On the basis of mode of nutrition they are autotrophic and heterotrophic
- On the basis of habitat where they live they are halophile, thermoacidophile

Now let us see classification of bacteria on basis of flagella
> Amphitrichous flagella: The flagella may be single or multiple and it extends from the two ends of the cell. Pseudomonas is an example of this flagella.

> Peritrichous flagella: When flagella is present all over the body surface that is in all directions it is termed as peritrichous flagella. Bacteria which possess flagella all over its body are termed as peritrichous bacteria. It causes movement of bacteria in every possible direction. It is present in bacillus typhosus

> lophotrichous flagella: The flagella is present in the form of tuft and it may be extended from one end of the cell or both the ends of the cell. Spirillum have lophotrichous flagella

> monotrichous flagella: As the name suggests it has a single flagella which is extended from one end of the cell. Vibrio has monotrichous flagella.

Note: Flagella are membrane bound extensions of the plasma membrane. They arise from centrioles. The number of flagella per cell is usually 1-4. They are longer in size. Flagella are commonly found at one end of the cell. Flagella helps in locomotion.