Crystal violet and safranin.

I (Carl Woese) classified the living organisms into three domains based on the differences in rRNA nucleotide sequence and lipid structure of the cell membrane. The three domains are Bacteria, Archae and Eukarya.

On exposure to UV radiation and chemicals, the prophage enters the lytic cycle.

(i) Wound tumour virus
(ii) Influenza virus

Viruses possess characters of both living and non-living and also they does not have well defined body organisation. Hence they are not included in the category of microorganism.

Protoplasmic fusion ~ Karyogamy ~ Meiosis ~ Spores production.

Study of fungi is called mycology. P.A. Micheli is considered as the founder of mycology.

Bacteria are prokaryotic, unicellular, ubiquitous, microscopic organisms. The study of bacteria is called bacteriology.

In this type of bacteria the hydrogen donor is H₂S and possess pigment called Bacterioviridin. Example: hlorobium

1. Rhizopus is a saprophytic fungus and grows on substrates like bread, jelly, leather, decaying vegetables and fruits.
2. It is commonly called 'Bread mould'. Since it easily grows on stale bread and is of common occurrence on bread.

1. Non-living things like mountains, boulders, sand dunes also grow by accumulating the material on their external surface.
2. But, this growth is considered as external growth in comparison to the growth of living things which is internal.

(a) Chlorobium - Photoautotrophic bacteria / Photolithotroph.
(b) Iron bacteria - Chemoautotrophic bacteria / Chemolithotroph.

Property of self-regulation and tendency to maintain a steady state within an external environment which is liable to change is called Homeostasis. It is essential for the living organisms.

(a) Lichens secrete organic acids like oxalic acids which corrodes the rock surface and helps in weathering of rocks, thus acting as pioneers in Xerosere.
(b) Usnic acid produced from lichens show antibiotic properties.
(c) Lichens are sensitive to air pollutants especially to sulphur-di-oxide. Therefore, they are considered as pollution indicators.
(d) The dye present in litmus paper used as acid base indicator in the laboratories is obtained from Roccella montagnei.
(e) Cladonia rangiferina (Reindeer moss) is used as food for animals living in Tundra regions.

Structure of T₄ Bacteriophage:
1. The T₄ phage is tadpole-shaped and consists of head, collar, tail, base plate and fibres.
2. The head is hexagonal which consists of about 2000 identical protein subunits.

3. The long helical tail consists of an inner tubular core which is connected to the head by a collar.
4. There is a base plate attached to the end of tail.
5. The base plate contains six spikes or tail fibres.
6. These fibres are used to attach the phage on the cell wall of bacterial host during replication.
7. A dsDNA molecule of about 50 \(\mu\)m is tightly packed inside the head.
8. The DNA is about 1000 times longer than the phage itself.

1. In the lysogenic cycle the phage DNA gets integrated into the DNA of the host cell and gets multiplied along with nucleic acid of the host. No independent viral particle is formed.
2. As soon as the phage injects its linear DNA into the host cell it becomes circular and integrates into the bacterial chromosome by recombination. The integrated phage DNA is now called prophage.
3. The activity of the prophage gene is repressed by two repressor proteins which are synthesized by phage genes. This checks the synthesis of new phages within the host cell.
4. However, each time the bacterial cell divides, the prophage multiplies along with the bacterial chromosome.
5. On exposure to UV radiation and chemicals the excision of phage DNA may occur and results in lytic cycle.

In mycorrihiza , relationship fungi absorbs nutrition from the root and in turn the hyphal network of mycorrhiza forming fungi helps the plant to absorb water and mineral nutrients from the soil.

1. Among these 'Phycomycetes' include fungal species of Oomycetes, Chytridiomycetes and Zygomycetes which are considered as lower fungi indicatlng algal origin of fungi.
2. Constantine J. Alexopoulos and Charles W. Mims in the year 1979 proposed the classification of fungi in the book entitled 'Introductory Mycology'.
3. They classified fungi into three divisions namely Gymnomycota, Mastigomycota and Amastigomycota. There are 8 subdivisions, 11 classes, 1 form class and 3 form subclasses in the classification proposed by them.
4. The salient features of some of the classes - Oomycetes, Zygomycetes, Ascomycetes, Basidiomycetes and Form class Deuteromycetes are discussed below.
5. With the advent of molecular methods, fungi traditionally studied by mycologists at present fall into 3 kingdom of Eukaryota.
6. The Eumycota include only fungi and protozoa and chromista which accommodates (myxomycetes, Oomycetes) formerly placed in fungi.

1. The classification is based on the complexity of cell structure and organization of thallus.
2. It is based on the mode of nutrition
3. Separation of fungi from plants
4. It shows the phylogeny of the organisms.

1. All living organisms are made up of cells which may be prokaryotic or eukaryotic.
2. Prokaryotesare unicellular; lack membrane bound nuclei and organelles like mitochondria, endoplasmic reticulum, golgi bodies and so on (Example: Bacteria and Blue green algae).
3. In Eukaryotes a definite nucleus and membrane bound organelles are present.
4. Eukaryotes may be unicellular (Amoeba) or multicellular (Oedogonium).

Penicillium - Conidia formation.
A- Conidium
B - Conidiophore

The Symbiotic association between fungal mycelium and roots of plants is called as mycorrhizae. Types.
1. Ectomycorrhizae
2. Endomycorrhizae
3. Ectendomycorrhizae

Phage-mediated DNA transfer is called transduction. It is of two types.
1. Generalised transduction.
2. Specialised or restricted transduction.