characteristics of kingdom Monera

General characters

1. They are most abundant microorganisms

2. They occur almost everywhere including extreme environments such as hot springs, deep oceans, snow and deserts.

3. Bacteria are the sole member of the kingdom Monera

4. Many live in or on other organisms as parasites

5. Cell structure is very simple but complex in behavior.

6. Show the most extensive metabolic diversity some are Autotrophic(Photosynthetic- use carbon dioxide and water and Heterotrophic(Use inorganic substance like nitrogen, Sulphur, iron etc.)

Classification of Bacteria

i) Monera includes unicellular(single celled) organisms.

ii) They are prokaryotes. Their chromosome material is not organized into nucleus. It lies directly inside the cytoplasm and is called nucleoid.

iii) Membrane bound cell organelles like mitochondria, Golgi apparatus, lysosomes etc. are absent

iv) Cell wall may or may not be present.

v) Mode of nutrition.

Classification of bacteria based on shape;

Spherical shape(Cocci) Ex: Staphylococci, Rod shape(Bacilli) Ex: Salmonella typhi, Spiral Shape(Spirilla) Ex: Trypanosoma, and Comma Shape(Vibrio) Ex: Vibrio Cholera.

Reproduction in bacteria

Bacteria reproduce by all method. Under favorable conditions they reproduce through spores, sexual reproduction may also takes place in a special way DNA transfer from one bacterium to another.

Major groups of Kingdom Monera and their examples.

Archaebacteria

• Unique since they live in the most harsh habitats such as Halophiles(salty areas), Thermoacidophiles(hot springs), Methogens(Marshy areas).
• Archaebacteria different from other bacteria in having different cell wall structure which provides capacity to survive in these extreme environmental conditions.
• Methanogens present in the guts of the ruminants animals such as cow and buffaloes and they are responsible for methane(biogas) production from their dung, cellulose(grass) digestion in ruminants.

Eubacteria(True Bacteria)

They are characterized by the presence of rigid cell wall and if motile, a flagellum is present.

1. Cyanobacteria(Blue Green Algae)

They have chlorophyll a similar to green plants; and they are photosynthetic autotrophs. They are unicellular, colonial or filamentous, marine or terrestrial algae. Colonial algae are surrounded by gelatinous sheath. They often form blooms in polluted water bodies called algal blooms. Some algae can fix atmospheric nitrogen in specialized cells called heterocyst's. Example- Nostoc and Anabaena.

2. Chemosynthetic Autotrophic Bacteria

Oxidize various inorganic substances such as nitrites, nitrates, ammonia, and use released energy for their ATP production. They play key role in recycling nutrients such as nitrogen, Sulphur, iron, phosphorous etc. 

3. Heterotrophic Bacteria

They are most abundant in nature and are important decomposers. They are beneficial in making curd from milk, production of antibiotics, fixing nitrogen in dicot plant roots. Some of them are pathogens, causing damage to humans, crops, cattle's and pets. In humans, they cause disease such as cholera, typhoid while they cause citrus canker in crop plants and anthrax in cattle.

4. Mycoplasma

They are smallest living cell and don't have cell wall can survive without oxygen. They are commonly called as joker of microbiology many are pathogens to humans, animals, and plants.