Tag: the world of microbes
Questions Related to the world of microbes
Some bacteria are considered plants as they
-
Are green in colour
-
Have rigid cell wall
-
Have chlorophyll
-
Have stomata
In bacteria the site for respiratory activity is found in
-
Episome
-
Microsome
-
Ribosome
-
Cell membrane$/$ Mesosome
In bacteria the site for respiratory activity is found in mesosomes. Mesosomes are folded invaginations in the cell membrane of bacteria. They increases the surface area required for respiration. They contain respiratory enzymes. It is the site of respiratory activity.
Sex factor of bacteria is
-
RNA
-
Sex pili
-
F-factor
-
Chromosome replicon
F-factor is also called as fertility factor. It is the sex factor of bacteria. It allows the transfers of genes from one bacterium carrying the factor to another bacterium lacking the factor by the process of conjugation. It is found in some bacteria only.
Which is not true of bacterial cell wall?
-
Not antigenic
-
Provides shape to bacterium
-
Not stainable with simple dyes
-
Made of mucopeptide
Murein of bacterial cell wall is derivative of
-
Vitamin
-
Fat
-
Organic acid
-
Sugar
The bacterial cell wall is made up of Peptidoglycan or murein. It is a polymer that is made up of sugars and amino acids. The sugar component is made up of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). NAM is then attached to an amino acid chain of L-alanine, D-glutamic acid, diaminopimelic acid (DAP) and D-alanine.
Bacterial cell membrane is made up of
-
Chitin
-
Cellulose
-
Proteins and phospholipids
-
Fats
Bacteria is a unicellular prokaryotic organism. It has a cell wall around the cell membrane. The bacterial cell membrane is made up of proteins and phospholipids. the proteins in are randomly distributed in the phospholipid bilayer of the cell membrane.
Teichoic acid is present in cell wall of
-
Bacteriophage
-
Mycoplasma
-
Nostoc
-
Pneumococcus
Some bacteria have a capsule outside cell wall. It is made of
-
Protein
-
Cellulose
-
Fat
-
Mucopolysaccharide
Some bacteria have a capsule outside cell wall. It is made up of mucopolysaccharide. The functions of mucopolysaccharide are;
- It enhances the ability of bacteria to cause disease.
- It protects cells from engulfment by macrophages.
- It protects cells from desiccation.
Why is a capsule advantageous to a bacterium?
-
It provides means of locomotion
-
It allows bacteria to "hide" from host's immune system
-
It allows the bacterium to attach to surface
-
It protects the bacterium from desiccation.
- Bacterial capsule usually consists of a polysaccharide layer that lies outside the cell envelope. The capsule is found in both gram-positive and gram-negative bacterium.
- The capsule is considered as virulence factor because it enhances the ability of bacteria to cause disease. It protects the bacterial cell from engulfment by macrophages.
- Capsules also contain water which protects the bacterium from desiccation.
Select the wrong statement of a bacterial cell
-
Mesosome is formed by extensions of plasma membrane into cell
-
Pili are elongated tubular structures made up of a protein
-
Flagellum is composed of filament, hook and basal body
-
Ribosomes are about 30 nm by 50 nm in size
-
Fimbriae are small bristle like fibres sprouting out of cell.