Page No 29:
Question 1:
Fill in the blanks:
(a) Microorganisms can be seen with the help of a _________.
(b) Blue green algae fix _________ directly from air to enhance fertility of soil.
(c) Alcohol is produced with the help of _________.
(d) Cholera is caused by _________.
Page No 29:
Question 2:
Tick the correct answer:
(a) Yeast is used in the production of
(i) sugar (ii) alcohol
(iii) hydrochloric acid (iv) oxygen
(b) The following is an antibiotic
(i) Sodium bicarbonate (ii) Streptomycin
(iii) Alcohol (iv) Yeast
(c) Carrier of malaria-causing protozoan is
(i) female Anopheles mosquito (ii) cockroach
(iii) housefly (iv) butterfly
(d) The most common carrier of communicable diseases is
(i) ant (ii) housefly
(iii) dragonfly (iv) spider
(e) The bread or idli dough rises because of
(i) heat (ii) grinding
(iii) growth of yeast cells (iv) kneading
(f) The process of conversion of sugar into alcohol is called
(i) nitrogen fixation (ii) moulding
(iii) fermentation (iv) infection
Page No 29:
Question 4:
Can microorganisms be seen with the naked eye? If not, how can they be seen?
Page No 30:
Question 9:
What are antibiotics? What precautions must be taken while taking antibiotics?
