Bacteriology is a branch of science under which we study about bacteria, like its metabolism, reproduction etc.
The General Characters Of Bacteria Are As Follow
- They are ubiquitous / omnipresent i.e. present in soil, air and water.
- They are unicellular, prokaryotic microorganism.
- The cell bears a thick rigid cell wall outside the plasma membrane (because of this character they are kept in plant kingdom).
- They have great variation in the mode of nutrition i.e. may be autotrophic and heterotrophic. In heterotrophism mode of nutrition they may be parasite, saprophyte or symbiotic in nature.
- They lack true chlorophyll but few photosynthetic bacteria have a special type of chlorophyll called bacteriochlorophyll.
- Because of prokaryotic nature they lack true nucleus (lacking nuclear membrane and nucleolus), genetic material is in the form of composite structure known as genophore / nucleotide / incipient nucleus.
- The cell wall of bacteria is made up of mucopeptide unlike the cell wall of plants (where it is made up of cellulose)
- They lack mitochondria, golgi apparatus, plastid and endoplasmic reticulum.
- They lack basic protein histone in their DNA.
- Ribosomes are of 70s type.
- At some places the plasma membrane invaginate in folds to form membrane.
- All the enzymes required for respiration are found in the cell membrane.
- Both DNA and RNA are present in the bacterial cell. DNA is in the form of single circular chromosome (therefore the cell is haploid).
- Vegetative reproduction is generally by binary fission, cyst, budding and gonidia.
- Asexual reproduction is by conidiophores, motile spores and endospore.
- True sexual reproduction is absent in bacteria but there are examples of genetic recombination which may be of following types viz. conjugation, transduction and transformation.
Plants Like Character In Bacteria
- In few bacteria cell wall is made up of cellulose.
- They show filamentous growth like some plants.
- Like plant autotrophic bacteria produces carbonic food by the use inorganic substances (CO2 and H2O).
- Structure and some mode of reproduction of bacteria is similar to some members of thallophyta.
- They absorb the nutritional substances in the soluble form through their cell wall (like plants).
- Bacteria has the ability to convert inorganic nitrogen into all types of -NH2 acids.
- Most of the transitional forms of bacteria and fungi are found in the nature.
Similarities Between Bacteria And Blue Green Algae
- Both groups bears a prokaryotic nucleus.
- Both are unicellular or colonial and the complicated structures are in filamentous form.
- Both groups have similar cell wall structure and cell division.
- Both lack the typical cellular organelles found in eukaryotic cells.
- Genetic material is DNA without histone proteins.
- Cells are surrounded by gelatinous sheath.
- Both have similar cell forms viz. spherical, cylindrical and spiral.
- No zoospores are formed during asexual reproduction in blue green algae and bacteria.
- Members of both the groups can withstand desiccation and high temperatures.
- Like saprophytic bacteria, blue green algae can live on dead organic matter in the absence of light.
- Genetic recombination is present in both blue green algae and bacteria.
Dissimilarities Between Cyanobacteria And Bacteria
- Cyanobacteria are always aflagellate while most of the bacteria are flagellate.
- All cyanobacteria are aerobic while many bacteria are anaerobic.
- All cyanobacteria have chlorophyll a for photosynthesis while bacteria bears bacteriochlorophyll.