Biology Online Quiz for BDS-Dental Entrance Exams on “Microbes in Industrial Products-3”.
1. What are the bioactive chemicals?
a) Chemicals which influence the functioning of the living system
b) Chemicals which actively participate
c) Chemicals which slough off other cells
d) Chemicals which help in the feedback mechanism
Answer: a
Clarification: Bioactive substances are those chemicals which influence the functioning of a living system and elicit a response for the same. E.g., statins, cyclosporine, streptokinase, lectins, etc.
2. Which of the following is the first organic acid produced through fermentation?
a) Acetic Acid
b) Lactic Acid
c) Citric Acid
d) Gallic Acid
Answer: b
Clarification: Lactic acid was the first organic acid produced through fermentation. It is obtained by the activity of several bacteria like Streptococcus lactis, Lactobacillus bulgaris, etc.
3. Which of the following organisms is responsible for the production of Citric Acid?
a) Bacteria
b) Archaebacteria
c) Protozoa
d) Yeast
Answer: d
Clarification: Species of Yeast like Mucor species, Aspergillus niger can ferment sugar to produce citric acid. Citric acid is a preservative and flavouring agent.
4. Which of the following organic acid is used for providing calcium to the infants?
a) Gallic acid
b) Gluconic acid
c) Butyric acid
d) Lactic acid
Answer: b
Clarification: Gluconic acid is manufactured by the agency of Penicillium purpurogenum, for use as calcium gluconate for providing calcium to infants, lactating mothers and treating milk fever in high milk yielding cows.
5. Butyric acid is formed by the activity of Aspergillus niger.
a) True
b) False
Answer: b
Clarification: Butyric acid or butanoic acid is formed by the activity of a bacterium, Clostridium butylicum. It is the acid that occurs in rancid butter.
6. Which of the following is a function of pectinases?
a) Clearing of fruit juices
b) Degumming of silk
c) Cleaning of hides
d) Manufacturing of soap
Answer: a
Clarification: Pectinases are obtained from fungi grown on pectin containing media. Pectinases are used in enhancing juice extraction from fruits, clearing of fruit juices, removing bitterness, retting of fibres and fermentation of green coffee.
7. Which of the following is not a function of Proteases?
a) Cleaning of hides
b) Synthesis of glue
c) Manufacturing of soap
d) Tenderness of meat
Answer: c
Clarification: Proteases are used for enhancing tenderness of the meat, extraction of fish liver oil, clarification and chill proofing of alcoholic drinks, softening of cheese and bread, cleaning of hides, degumming of silk, synthesis of glue, etc.
8. Which of the following is not a function of amylases?
a) Manufacturing of soap
b) Sweetening of bread
c) Separation and desizing of fibres
d) Clearing starch related turbidity in fruit juices
Answer: a
Clarification: Amylases are starch digesting enzymes that are used in softening and sweetening of bread, separation and desizing of fibres, clearing of starch related turbidity in juices and clearing starch related stains on utensils and clothes.
9. Depending on the type of raw material used for fermentation and the type of processing, different types of alcoholic drinks are obtained.
a) True
b) False
Answer: a
Clarification: We can obtain different types of alcoholic drinks by using different raw materials for fermentation and by using different techniques for processing like processing alcoholic drinks with distillation or without distillation. For example, wine and beer are produced without distillation whereas whisky, brandy and rum are produced by distillation.
10. Which of the following is the function of lipases?
a) Manufacturing of soaps
b) Clearing of hides
c) Sweetening of bread
d) Removing bitterness
Answer: a
Clarification: Lipases are lipid digesting enzymes used in flavouring cheese, hydrolysing oils for manufacture of soap and in detergent formulations for removing fat-based stains.
11. Colonies of which microbe can be seen in the diagram below?
a) Fungi
b) Bacteria
c) Virus
d) Protozoa
Answer: a
Clarification: The given diagram represents a fungal colony growing in a petri-dish. These colonies can be seen with naked eyes and such cultures are useful in the studies of micro-organisms.
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