Question:
Suggest a suitable word for each of the following statements.
(a) Chemicals added to food to prevent growth of micro organisms.
(b) Nitrogen-fixing micro organism present in the root nodules of legumes.
(c) Agent which spreads pathogens from one place to another.
(d) Chemicals which kill or stop the growth of pathogens.
Solution:
(a) Preservatives are the chemicals added in food. They prevent microbial infection without altering the taste or appearance.
(b) Rhizobium are the nitrogen fixing bacteria which fix the atmospheric nitrogen into that form (i.e. nitrates, nitraties) which is usable for plants.
(c) Carrier/Vector are the modes of transmission of a disease.
(d) Antibiotics are the antimicrobial agents for inhibiting or killing the growth of microbes.