Kingdom : Monera
The Kingdom Monera includes all prokaryotes. Monerans are the most primitive forms of life, originating from more ancient living stock termed progenote. The kingdom Monera includes eubacteria and archaebacteria. Eubacteria includes Cyanobacteria. Actinomycetes, Mycoplasma, Rickettsiae, Chlamydiae and Spirochaetes etc.
Classification of Monera
1.In 4 kingdom system , a new kingdom was created to accommodate all prokaryotic organisms i.e, eubacteria and archaebacteria. Copeland called it kingdom Mycnota. It was called ‘Monera’ by Daugherty and Allen.
2.Actually, archaebateria differ from eubacteria in many respects and resemble eukaryotes in some ways.
- (i) Carl Woese separated the archaebacteria from eubacteria on the basis of some major differences such as the absence of peptidoglycan in the cell walls of the former and the occurrence of branched chain lipids ( a monolayer instead of a phospholipid bilayer ) in the membrane.
(ii) Therefore , 6 kingdoms given by Carl Woese are
Kingdom-1 – Archaebacteria
Kingdom-2 – Eubacteria
Kingdom-3 – Protista
Kingdom-4 – Fungi
Kingdom-5 – Plantae
Kingdom-6 – Animalia
Salient Features of Monera
1.These are unicellular, colonial, multicellular prokaryotic organisms without nuclear membrane, nucleolus, chromatin and histone proteins.
- Cell wall is made up of peptidoglycan (exceptions are Archaebacteria and Mycoplasma)
- Membrane bound organelles are absent.
- Cyclosis is absent and ribosomes are of 70 S type.
- Respiratory enzymes are found associated with plasma membrane.
- Nucleoid or genophore or incipient nucleus or prochromosome is composed of naked DNA, RNA and non-histone proteins.
- Reproduction by asexual method.
- cell division is amitotic type and lacks spindle formation.