C. Suggest a suitable word for each of the following statements:-
a. Chemicals added tofood toprevent growth ofmicroorganisms.
b. Nitrogen-fixing microorganism 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.
Answers
Answer:
The following are the suitable words for each of the following statements –
a. Chemicals added to food to prevent growth of microorganisms. – Preservatives
Preservatives are the chemicals that are added to food so that it is safe from microbes. By adding this, the taste of the food doesn't change. Example - Oil, Salt, certain chemicals, etc.
b. Nitrogen fixing microorganism present in root nodules of legumes. – Rhizobium Bacteria
Rhizobium bacteria is present in the root nodules of leguminous plants. These leguminous plants lead nitrogen in the form of nitrates and nitrites. And the rhizobium bacteria in tern gets a place to stay. Hence, rhizobium bacteria and the plants form a symbiotic relation. The rhizobium bacteria converts gaseous nitrogen in the form of nitrates and nitrites for the use of leguminous plants.
c. Agent which spreads pathogens from one place to another. – Vector/Carrier
Vector or Carrier are the organisms or things that help in the spread of pathogens. For example - Mosquito is the vector for diseases like malaria. The other Vector includes aur, water, etc.
d. Chemicals which will kill or stop the growth of pathogens. – Antibiotic
Antibiotics chemicals which help in killing a stopping the growth of pathogens or the disease causing microorganisms. One example of such antibiotic is Penicillin.