Bacteria

• Bacteria are the sole member of kingdom monera.
• They are most abundant micro-organism.
• Hundreds of bacteria found in the handful of soil.
• They also live in extreme habitats such as hot-springs,deserts,snow & deep oceans. Many are parasites.
• Based on the shape, bacteria are 4 categories.
• 1 Coccus (Spherical)
• 2 Bacillus (Rod-shaped)
• 3 Vibrium (Comma-shaped)
• 4 Spirillum (Spiral)
• Bacterial structure is very simple but they are complex in behaviour and show extensive metabolic diversity.
• Some bacteria are autotrophic (synthesize food from inorganic substrates).
• Majority are heterotrophs (they do not synthesize the food but depend on other organisms or on dead organic matter for food).