i. Microorganisms can be seen with the help of a microscope.
ii. Blue green algae fix nitrogen directly from air to enhance fertility of soil.
iii. Alcohol is produced with the help of yeast.
iv. Cholera is caused by bacteria.
v. Carrier of malaria-causing protozoan is female Anopheles mosquito.
vi. The bread or idli dough rises because of growth of yeast cells.
i. Housefly is the common carrier of communicable diseases. True
ii. Amoeba lives in colonies. False
iii. Bacteria are also involved in the making of cheese, pickles and many other food items. True
iv. Polio drops given to children are actually a vaccine. True
Ans. Malaria is caused by protozoa.
Ans. Aedes mosquito acts as carrier of dengue virus.
Ans. Polio and smallpox
Ans. Chlamydomonas and Spirogyra
Ans. Amoeba and Paramecium
Ans. Cholera and typhoid are caused by bacteria.
Ans. Bread mould, Penicillium and Aspergillus
Ans. In 1929, Alexander Fleming discovered penicillin.
Ans. Typhoid and tuberculosis (TB)
Ans. Foot and mouth disease of cattle is caused by a virus.
Ans. Edward Jenner discovered the vaccine for smallpox in 1798.
Ans. Diseases like dysentery and malaria are caused by protozoans.
Ans. Streptomycin, tetracycline and erythromycin
Ans. Meat and fish are covered with dry salt to check the growth of bacteria.
Ans. The process of conversion of sugar into alcohol is called fermentation.
Ans. We boil milk before storing because boiling kills many microorganisms.
Ans. Citrus canker is caused by bacteria and transmitted through air.
Ans. Antibiotics are not effective against cold and flu as these are caused by viruses.
Ans. Yellow vein mosaic of bhindi (Okra) is caused by virus and transmitted through insect.
Ans. They can be controlled by the use of certain chemicals which kill the microbes.
Ans. Rust of wheat is caused by fungi and transmitted through air and seeds.