Structure nutrition and reproduction in bacteria
Answers
Answer:
“Bacteria are unicellular organisms belonging to the prokaryotic group where the organisms lack a few organelles and a true nucleus”.
Explanation:
Structure of Bacteria
The structure of bacteria is known for its simple body design. Bacteria are single-celled microorganisms with the absence of the nucleus and other cell organelles; hence, they are classified as prokaryotic organisms.
They are also very versatile organisms, surviving in extremely inhospitable conditions. Such organisms are called extremophiles. Extremophiles are further categorized into various types based on the types of environments they inhabit:
Thermophiles
Acidophiles
Alkaliphiles
Osmophiles
Barophiles
Cryophiles
Another fascinating feature of bacteria is their protective cell wall, which is made up of a special protein called peptidoglycan. This particular protein isn’t found anywhere else in nature except in the cell walls of bacteria.
But few of them are devoid of this cell wall, and others have a third protection layer called capsule. On the outer layer, one or more flagella or pili is attached, and it functions as a locomotory organ. Pili can also help certain bacteria to attach themselves to the host’s cells. They do not contain any cell organelle as in animal or plant cell except for ribosomes.
Ribosomes are the sites of protein synthesis. In addition to this DNA, they have an extra circular DNA called plasmid. These plasmids make some strains of bacteria resistant to antibiotics.
Also Read: Gram Positive Bacteria
Classification of Bacteria
Bacteria can be classified into various categories based on their features and characteristics. The classification of bacteria is mainly based on the following:
Shape
Composition of the cell wall
Mode of respiration
Mode of nutrition
Classification of bacteria based on Shape
Type of Classification Examples
Bacillus (Rod-shaped)
Escherichia coli (E. coli)
Spirilla or spirochete (Spiral)
Spirillum volutans
Coccus (Sphere)
Streptococcus pneumoniae
Vibrio (Comma-shaped) Vibrio cholerae
Classification of bacteria based on the Composition of the Cell Wall
Type of Classification Examples
Peptidoglycan cell wall
Gram-positive bacteria
Lipopolysaccharide cell wall Gram-negative bacteria
Classification of bacteria based on the Mode of Nutrition
Type of Classification Examples
Autotrophic Bacteria
Cyanobacteria
Heterotrophic Bacteria All disease-causing bacteria