Sample Qs-Microorganism

1.(a) State the difference between bacteria and virus in the following aspect : [3m]
i. Structure
ii.Method of reproduction
iii.Nutrition.
(b) (i) Parasites can cause diseases. State 3 main ways how parasitic diseases can be
transmitted in a community . [3m]
(ii) Ringworm is a disease caused by fungus. Explain how transmission of this pathogen
can be stopped. [3m]
(c) Microorganisms can be useful to human. Explain the importance of microorganisms :
(i) In food industry. [3m]
(ii) In Nitrogen cycle [3m]
(iii) Production of insulin [3m]

Suggested Answer:

1(a)Structure :
- Bacteria enclosed by cell wall made of glycoprotein, but virus only have protein coat // Bacteria have nucleus but virus only contain RNA / DNA

Method of reproduction :
- Bacteria reproduce asexually by binary fission , but virus only replicate the DNA/RNA in the host

Nutrition :
- Bacteria can be synthesis organic substances via chemosynthesis (autotroph) or feed organic substances from other organisms (heterotroph) but viruses are strickly parasit (absorp nutrient from the host)

(b)(i)- vector such as rat, housefly or others
- by food / water
- by droplet transmission
(ii)- do not share clothes with others
- wash / clean all part of your body and make sure it dry
- use anti-fungus cream
- take vitamin C
(c) (i)- Yeast used in cake industry / wine industry
- bacteria used in chocolate / dairy product industry
- fungus used as a food
(ii)- Nitrogen fixing bacteria convert the nitrogen gas to nitrates in the soil (example Rhizobium sp and Nostoc)
- Bacteria and fungi decompose dead organisms to form ammonia
- Nitrosomonas and nitrobacter convert ammonia to nitrites and nitrites to nitrates.
(iii)- Fragmen of DNA which control the formation of insulin from pancreas was inserted in the DNA of bacteria
- That bacteria will be cultured in a specific medium.
-That bacteria has ability to produce insulin in big amount and faster.