- Which of the following is a free-living nitrogen-fixing bacterium?
A. Rhizobium
B. Azotobacter
C. Penicillium
D. Saccharomyces
Answer: B. Azotobacter
Explanation:
Azotobacter is a free-living nitrogen-fixing bacterium that is found in soil and helps to increase the nitrogen content without forming symbiotic relationships with plants.
- The organism that produces the antibiotic streptomycin is:
A. Streptomyces griseus
B. Penicillium notatum
C. Aspergillus niger
D. Rhizopus stolonifer
Answer: A. Streptomyces griseus
Explanation:
Streptomyces griseus is a bacterium that produces streptomycin, an antibiotic used to treat bacterial infections such as tuberculosis.
- Which microorganism is commonly used in sewage treatment plants?
A. Rhizobium
B. Azospirillum
C. Methanobacterium
D. Activated sludge bacteria
Answer: D. Activated sludge bacteria
Explanation:
In sewage treatment plants, aerobic bacteria in the activated sludge process break down organic matter in the wastewater, leading to its purification.
- Monascus purpureus is used for the production of:
A. Ethanol
B. Statins
C. Antibiotics
D. Biogas
Answer: B. Statins
Explanation:
Monascus purpureus, a red yeast, produces statins, which are cholesterol-lowering drugs used in the prevention of cardiovascular diseases.
- The term “flocs” in sewage treatment refers to:
A. Solid waste in sewage
B. Bacteria and fungi associated with sewage sludge
C. Viruses in sewage
D. Chemical coagulants
Answer: B. Bacteria and fungi associated with sewage sludge
Explanation:
“Flocs” are clusters of bacteria and fungi in activated sludge that help break down organic pollutants during the secondary treatment of sewage.
- The production of alcoholic beverages like beer and wine is primarily carried out by:
A. Streptococcus lactis
B. Saccharomyces cerevisiae
C. Clostridium butylicum
D. Azotobacter
Answer: B. Saccharomyces cerevisiae
Explanation:
Saccharomyces cerevisiae (brewer’s yeast) is used in the fermentation process to convert sugars into alcohol, which is essential for the production of beer and wine.
- Which of the following microbes is used in the production of bioinsecticides?
A. Bacillus thuringiensis
B. Penicillium notatum
C. Streptococcus thermophilus
D. Rhizobium
Answer: A. Bacillus thuringiensis
Explanation:
Bacillus thuringiensis produces proteins that are toxic to insect larvae, making it an effective bioinsecticide used in organic farming.
- The first antibiotic discovered by Alexander Fleming was:
A. Streptomycin
B. Penicillin
C. Tetracycline
D. Erythromycin
Answer: B. Penicillin
Explanation:
Penicillin was the first antibiotic discovered by Alexander Fleming in 1928. It was derived from the fungus Penicillium notatum and has been used to treat bacterial infections.
- The “blue-green algae” that are commonly used as biofertilizers in paddy fields are:
A. Anabaena and Nostoc
B. Penicillium and Rhizopus
C. Aspergillus and Rhizopus
D. Streptococcus and Lactobacillus
Answer: A. Anabaena and Nostoc
Explanation:
Cyanobacteria like Anabaena and Nostoc fix atmospheric nitrogen in paddy fields, acting as biofertilizers that help increase soil fertility.
- In the context of industrial biotechnology, the production of citric acid involves which microorganism?
A. Rhizopus stolonifer
B. Aspergillus niger
C. Saccharomyces cerevisiae
D. Penicillium chrysogenum
Answer: B. Aspergillus niger
Explanation:
Aspergillus niger is widely used in the industrial production of citric acid, which is an important additive in the food and beverage industry.
Leave a comment