Bacteria Types and Classification

All Bacteria have the following characteristics:

• Unicellular and stick together in colonies
• Are prokaryotic (no nucleus, vacuoles, mitochondria or chloroplasts)
• They have a single chromosome in a DNA loop
• They reproduce asexually by binary fission
• Live in moist environment and are inactive in dry environments

Two groups of Bacteria

1.  Archaebacteria – primitive bacteria that live in harsh environments

2.  Eubacteria – most common bacteria eg: E. Coli

Other ways of classifying bacteria are:

3.  Aerobic or anaerobic

4.  Autotroph or heterotroph

Bacteria Reproduction:

BINARY FISSION

–      similar to mitosis (simple cell division)

STEPS:

1. DNA replicates (doubles)
2. a cross wall forms dividing the cell into two identical bacteria

Some bacteria (eg: E.Coli and Salmonella) reproduce by conjugation (sexual reproduction)