1. The bacteria which retain the violet colour in Gram's staining procedure are called as Gram +ve.
2. Eg: Pneumococcus, Streptococcus.

1. They are most primitive prokaryotes.
2. They are found in extreme environmental conditions. Eg: Hot springs.
3. Unique feature is presence of lipids like glycerol and isopropyl ethers in their cell membrane. Hence the membrane shows resistance against cell wall antibiotics.
Eg: Methanobacterium.

1. Can be crystallized.
2. Absence of metabolism.
3. Inactive outside the host.
4. Do not show functional autonomy.
5. Energy producing enzyme system absent.

1. Presence of nucleic acid and protein.
2. Capable of mutation.
3. Ability to multiply within living cells.
4. Ability to infect and cause diseases III living beings.
5. Show irritability.
6. Host-specific.

During crop rotations and mixed cropping. Farmers plant leguminous crops to increase the soil fertility.

S.No	Beneficial aspects	Bacteria	Role
1.	Ammonification	1. Bacillus ramosus 2.Bacillus mycoides	Convert complex proteins in the dead bodies of plants and animals into ammonia which is later converted into ammonium salt
2.	Nitrification	1. Nitrobacter 2. Nitrosomonas	Convert ammonium salts into nitrites and nitrates
3.	Nitrogen fixation	1. Azotobacter 2. Clostridium 3. Rhizobium	(i) Converting atmospheric nitrogen into organic nitrogen
			(ii) The nitrogenous compounds are also oxidized to nitrogen
			(iii) All these activities of bacteria increase soil fertility

S.No	Criteria	Monera
1.	Cell type	Prokaryotic
2.	Level of organization	Mostly unicellular, rarely Multicellular
3.	Cell wall	Present (made up of peptidoglycan and mucopeptides)
4.	Nutrition	Autotrophic (Phototrophic, Chemoautotrophic) Heterotrophic (Parasitic and Saprophytic)
5.	Motility	Motile or non-motile
6.	Organisms	Archaebacteria, Eubacteria, Cyanobacteria, Actinomycetes and Mycoplasma

S.No	Beneficial aspects	Bacteria	Role
1.	Soil fertility
	Ammonification		Bacillus ramosus	Convert complex proteins in the dead bodies of plants and animals into ammonia which is later converted into ammonium salt.
2.	Antibiotics
	Chloromycetin		Streptomyces venezuelae	Cures typhoid fever.
3.	Industrial use
	a) Cheese		Lactobacillus lactis	Convert milk to cheese.
	b) Vitamins		Escherichia coli	Produces Vitamin K and vitamin B complex in human intestine.
4.	Curing of Tea and Tobacco
			Bacillus megatherium	Adding special flavour and aroma to tea and tobacco leaves by fermentation.
5.	Diseases
	a) Bacterial blight		Xanthomonas oryzae	Affects rice crop.
	b) Cholera		Vibrio cholerae	Affects human beings.
	c) Anthrax		Bacillus anthracis	Affects sheep.

General characteristic features of Bacteria :
1. They are prokaryotic organisms and lack nuclear membrane and membrane bound organelles.
2. The genetic material is called nucleoid or genophore or incipient nucleus.
3. The cell wall is made up of polysaccharides and proteins.
4. Most of them lack chlorophyll, hence they are heterotrophic but some are autotrophic and possess Bacteriochlorophyll.
5. They reproduce vegetatively by fission and endospore formation.
6. They exhibit variations which are due to genetic recombination and is achieved through conjugation, transformation and transduction.
7. The shape and flagellation of the bacteria varies in different types of bacteria

Criteria	Monera	Protista	Fungi	Plantae	Animalia
Cell type	Prokaryotic	Eukaryotic	Eukaryotic	Eukaryotic	Eukaryotic
Level of organization	Unicellular	Unicellular	Multicellular and Unicellular	Tissue/Organ	Tissue/Organ/Organ system.
Cell wall	Present (made up of Peptidoglycan  and Mucopeptides ).	Present in some  (made up of cellulose), absent in others.	Present (made up of chitin).	Present (made up of cellulose).	Absent.
Nutrition	Autotrophic, (Phototrophic,  Chemoautotrophic) Heterotrophic  (Parasitic and Saprophytic).	Autotrophic - Photosynthetic. Heterotrophic.	Heterotrophic Parasitic or Saprophytic.	Autotrophic (Photosynthetic).	Heterotrophic (Holozoic).
Motility	Motile or Non-motile	Motile or Non-motile	Non-motile	Mostly Non - motile	Mostly Motile
Organisms	Archaebacteria, Eubacteria,  Cyanobacteria, Actinomycetes and Mycoplasma.	Chrysophytes, Dinoflagellates,  Euglenoids, Slime molds, Amoeba, Plasmodium, Trypanosoma, Paramecium	Yeast, Mushrooms and Molds.	Algae, Bryophytes, Pteridophytes,  Gymnosperms and Angiosperms.	Sponges, Invertebrates  and Vertebrates.

(i) The symbiotic association between algae and fungi is called lichens.
(ii) The algal partner is called Phycobiont or Photobiont and the fungal partner is called Mycobiont.
(iii) Algae provide nutrition for fungal partner in turn fungi provide protection and also help to fix the thallus to the substratum through rhizinae.
(iv) Asexual reproduction takes place through fragmentation, Soredia and Isidia. Phycobionts reproduce by akinetes, hormogonia, aplanospore, etc., Mycobionts undergo sexual reproduction and produce ascocarps.
Classification:
(i) Based on the habitat lichens are classified into following types: Corticolous (on Bark) Lignicolous (on Wood) Saxicolous (on rocks) Terricolous (on ground) Marine (on siliceous rocks of sea) Fresh water(on siliceous rock of fresh water).
(ii) On the basis of morphology of the thallus they are divided into Leprose (a distinct fungal layer is absent) Crustose-crust like; Foliose-leaf like; Fruticose-branched pendulous shrub like.
(iii) The distribution of algal cells distinguishes lichens into two forms namely Homoiomerous (Algal cells evenly distributed in the thallus) and Heteromerous (a distinct layer of algae and fungi present)
(iv) If the fungal partner of lichen belongs to ascomycetes, it is called Ascolichen and if it is basidiomycetes it is called Basidiolichen.

(i) R.H.Whittaker, an American taxonomist proposed five kingdom classification in the year 1969.
(ii) The Kingdoms include Monera, Protista, Fungi, Plantae and Animalia.
(iii) The criteria adopted for the classification include cell structure, thallus organization, mode of nutrition, reproduction and phylogenetic relationship. The merits and demerits are as follows:
Merits:
(i) The classification is based on the complexity of cell structure and organization of thallus.
(ii) It is based on the mode of nutrition.
(iii) Separation of fungi from plants.
(iv) It shows the phylogeny of the organisms.
Demerits:
(i) The kingdom Monera and Protista accommodate both autotrophic and heterotrophic organisms, cell wall lacking and cell wall bearing organisms thus making these two groups more heterogeneous.
(ii) Viruses were not included in the system.
 

Fungi growing on dung are called coprophilous fungi. Eg : Pilobolus.

1. They are prokaryotes.
2. The genetic material is called nucleoid and lacks nuclear membrane.
3. They reproduce by fission

The word virus is derived from Latin meaning 'Poison' .