Question

write 10 lines on the usefulness of micro-organisms in our lives

Answer 1

Write 10 lines on the usefulness of microorganisms in our lives.

Solution: Micro-organisms are too small to be seen through naked eyes. However, they are vital to plants and the environment.

i. Lactobacillus is used to form curd from milk.

ii. Rhizobiums present in the roots of pulse plants fix nitrogen from air and supply nitrogen compounds to the pulse plants.

iii. Micro-organisms are also used in winemaking, baking, pickling, and other food making processes.

iv. Alcoholic fermentation by yeast is widely used in the preparation of wine and bread.

v. Microbes are used to reduce pollution. For example, decomposers such as bacteria and fungi break down dead bodies and excreta to form inorganic compounds, which can be absorbed by plants.

vi. Microbes also play an important role in the preparation of medicines. Antibiotics are chemicals produced by micro-organisms to kill bacteria. Penicillin is an antibiotic made from Penicillium.

vii. Bacteria present in our intestine helps in proper digestion and release Vitamin B which is absorbed by intestine.

viii. Many vaccines are prepared from micro-organisms. These vaccines are given to children to protect them from disease.

ix. Certain microbes are also used in the biological treatment of sewage and industrial effluents.

x. Yeast is used in making idli, bhaturas, bread, pastries and cakes.

Answer 2

(i) Bacteria cause the decay of dead plants and animals.
(ii) Nitrogen fixing bacteria convert the atmospheric nitrogen into nitrates.
(iii) Bacteria are used in the production of vinegar, curd, cheese, etc.
(iv) Bacteria are used in sewage disposal plants.
(v) Scientists have discovered ways to change bacteria so that they produce valuable medical,