Cholera
Causative agent: Vibrio Cholerae

i) Malaria caused by female Anopheles mosquito.
ii) Dengue caused by Aedes aegypti mosquito.

i) Diarrhoea is caused by Rota virus.
ii) Prevention:
a) Don't take contaminated food.
b) Don't stagnant contaminated water around the living areas.

Alexander Fleming.
Name of Antibiotic: Streptomycin, Erythromycin, Bacitracin

Tuberculosis, Diphtheria, whooping cough, common cold, chickenpox are the diseases associated with respiratory system.

1. Yes, Chicken pox would not occur again for sanjay .
2. Because, once it occured, his body will derive immunity against that disease .
3. This kind of immunity is developed by our body, during the first infection of chicken pox pathogen .
4. The antibodies produced in the blood remain for a long period and kill the simile pathogens, whenever they enter the body.

Triple antigen is a combined vaccine for protection against Diphtheria, Pertussis (whooping cough) and Tetanus.

i) The vector of malarial parasite is female Anopheles mosquito.
ii) Malaria is caused by Plasmodium falciparum is malignant and fatal.

Possible causes: Infected by the virus through, contaminated food and water and oral route.
Possible solution: Proper sanitation and hygiene in the babies family.

In one such disease, there is a progressive decrease in WBC of the patient.
a) Name the disease and its causative agent.
Name of the disease : AIDS
Causative agent :. HIV - Human immuno deficiency virus
b) Name the type of WBC affected during infection.
Type of WBC affected by HIV : T-Iymphocytes
c) How does the blood of a patient come in contact with blood of healthy patient?
Mode of Transmission : Sexual contact, transfusion of unscreened blood, by surgical equipments from infected mother to the foetus.
d) Suggest three methods that help in preventing such infection.
Prevention :
1. Disposable syringes and needles should be used .
2. Protected and safe sexual contact.
3. Screening of blood before blood transfusion .
4. Avoid sharing shaving blades/razors.

Typhoid causative agent: Salmonella typhi
Mode of entry of the pathogen:
Through food and water contaminated with faeces of infected person and through houseflies.
Diagnostic symptoms:
High fever, weakness, abdominal pain, headache, loss of appetite, rashes on chest and upper abdomen.
Organ affected in severe cases:
Human Digestive system gets affected and the blood can carry the bacteria to other organs including the lungs, liver, gall bladder and kidneys.

The immunization schedule indicates the age at which the vaccine should be administered to protect the children from infectious diseases.

Viruses are categorized as
i) Plant virus:
Virus that infect plants,
eg: Tobacco mosaic virus, cauliflower mosaic virus, Potato virus.

ii) Animal virus:
Virus that infect animals
eg: Adenovirus, Retrovirus(HIV), Influenza virus

iii) Bacteriophages:
Virus that infect bacterial cells.
eg: T4 Bacteriophage

Microbes in Agriculture:
Microbes play an important role in agriculture as biocontrol agents and biofertilizers. Microbes play a vital role in the cycling of elements like carbon, nitrogen, oxygen, sulphur and phosphorus.
(i) Microbes as biocontrol agents:
1. Microorganisms used for controlling harmful or pathogenic organisms and pests of plants are called as biocontrol agents (Biopesticides).
2. Bacillus thuringiensis (Bt) is a species of bacteria that produces a protein called as 'cry' protein.
3. This protein is toxic to the insect larva and kills them.
4. Spores of B thuringiensis are available in sachets, which are dissolved in water and sprayed on plants infected with insect larva.
(ii) Microbes as biofertilizers
1. Microorganisms which enrich the soil with nutrients are called as biofertilizers.
2. Bacteria, cyanobacteria and fungi are the main sources of biofertilizers.
3. Nitrogen is one of the main source of plant nutrients.
4. Atmospheric nitrogen has to be converted to available form of nitrogen.
5. This is done by microbes either in free living conditions or by having symbiotic relationship with the plants.
6. e.g. Nitrosomonas Nostoc (free living), symbiotic microbes like Rhizobium, Frankia.
Microbes in Industries:
Microorganisms play an important role in the production of wide variety of valuable products for the welfare of human beings.
i) Production of fermented beverages:
Beverages like wine are produced by fermentation of grape fruits by Saccharomyces cerevisiae.
ii) Curing of coffee beans, tea leaves and tobacco leaves:
1. Beans of coffee and cocoa, leaves of tea and tobacco are fermented by the bacteria Bacillus megaterium.
2. This gives the special aroma.
iii) Production of curd:
Lactobacillus sp. converts milk to curd.
iv) Production of organic acids, enzymes and vitamins:
1. Oxalic acid, acetic acid and citric acid are produced by fungus Aspergillus niger.
2. Enzymes like lipases, invertase, proteases, and glucose oxidase are derived from microbes. Yeasts are rich source of vitamin-B complex.

Based on the shapes, bacteria are grouped as

1. Spherical shaped bacteria called as cocci or coccus for a single cell.
2. Rod shaped bacteria called as bacilli or bacillus for a single cell.
3. Spiral shaped bacteria called as spirilla or spirillum for single cell.

1. Pathogen
In Greek 'pathos' means suffering 'genes' means "producer of' pathogen is defined as anything that can produce disease.
2. Bacteriophages
Virus that infect bacterial cells is called Bacteriophages.
3. Vaccines
Vaccines are preparation of living or killed microorganisms or their products used for prevention or treatment of diseases.
4. Prions
Prions means proteinaceous infective particles. They are viral particles which contains only proteins. They do not contain nucleic acids.