Question 1Microorganisms are placed under ____________,__________,__________, algae and viruses.
Bacteria, fungi, protozoa
Question 7What do you understand by microorganisms? Describe their useful and harmful effects.
Microorganisms are very small and can survive in almost all kinds of environmental conditions. The microorganisms help in decomposition of wastes in sewage treatment plants. Yeasts are unicellular and saprophytic fungi, which are used in fermentation to produce beer, wine and other beverages.
Harmful effects of microorganims are, some of the fungi damage and spoil food products, leather, paper and textiles, whereas others are pathogenic to crops and animals. Protozoans cause serious diseases like dysentery and malaria.
Question 8Write a note on the animal diseases caused by microorganism ?
Some Diseases Caused by Microorganisms
|Mumps||Painful swelling near the jaw on one or both sides.||Mumps in males over the age of 11 may affect the testes, but it rarely results in sterility.|
|Chicken pox||Small red spots which turn to blisters, andthen to scabs.||Chicken pox affects children mildly but in adults it is severe. The same virus causes shingles.|
|Rabies||Fever, delirium, convulsions, paralysis. The throat muscles tighten so that it is impossible even to drink.||Rabies can infect all animals - fox, bats, etc. but it is mainly a serious risk to human beings ,if domestic animals are infected.|
|Tuberculosis||cough and damage to lungs.||Many people who are infected by TB germs do not develop TB. They develop a natural immunity to TB.|
|Typhoid||Fever, constipation, dry cough.||Can be prevented by proper sewage disposal.|
|Cholera||diarrhoea, dehydration and collapse.||Can be prevented by using clean water and clean food.|
Question 9Write a note on the plant diseases caused by microorganism?
|Plant diseases||Micro organism||Mode of transmission|
|Rust of wheat||fungi||Air seeds|
|Yellow vein Virus Insect mosaic of bhindi (Okra)||Virus||Insect|
Question 10Write an short note essay on the beneficial aspects of microorganisms.
Microbes improve soil aggregation, which influences soil-water movement and aeration. They enhance nutrient levels through nutrient cycling and organic-matter decomposition. They are essential in developing soil organic matter. Microbes degrade, mineralize and immobilize materials (organic matter, pesticides, and fertilizers) that turf managers apply to the soil. Microbes also form symbiotic (mutually beneficial) relationships with plants.
Question 11Write the methods of food preservation
Sodium benzoate and sodium metabisulphite are common preservatives. These are also used in the jams and squashes to check their spoilage.
Preservation by Common Salt
Salting is also used to preserve Alma, raw mangoes, tamarind,
Preservation by Sugar
Jams, jellies and squashes are preserved by sugar.
Preservation by Oil and Vinegar
Use of oil and vinegar prevents spoilage of pickles
Heat and Cold Treatments
Boiling kills many microorganisms. Low temperature inhibits the growth of microbes.
Storage and Packing