D. Long answer type questions
1. What are microorganisms? What is the study of microorganisms called? Mention some uses of
microorganisms?
2. Classify microorganisms. Give characteristic features of each class with an example each
3. Explain the different microbes that cause diseases in humans, plants and animals.
4. Differentiate between antibiotics and vaccines.
5. Mention the different methods of food preservation.
6. Describe the nitrogen cycle in detail with the help of a diagram.
Answers
Ans1. A microorganism, or microbe, is a microscopic organism, which may exist in its single-celled form or in a colony of cells. The study of microorganisms is microbiologist. Microorganisms help in the production of many food items, making medicines, keeping the environment clean, in manufacturing and in research.
2. Microorganisms are divided into seven types: bacteria, archaea, protozoa, algae, fungi, viruses, and multicellular animal parasites ( helminths ).
Each type has a characteristic cellular composition, morphology, mean of locomotion, and reproduction.
3. microbes are called disease-causing microbes and can make humans, animals and plants sick by causing infection and disease. Most microbes belong to four major groups: bacteria, viruses, protozoa or fungi. (To find out more, see the “Bacteria/Viruses/Protozoa” fact sheets).
4.Antibiotics and vaccines are in some ways opposites. Antibiotics kill indiscriminately, whereas vaccines are highly targeted. Antibiotics are used to treat severe infection, whereas vaccines prevent infections from ever becoming established
5. methods of preservation are drying, refrigeration, and fermentation. Modern methods include canning, pasteurization, freezing, irradiation, and the addition of chemicals. Advances in packaging materials have played an important role in modern food preservation.
6.
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. ... Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.
