1. : Environmental microbiology is the study of:
(A) Microbes causing human diseases only
(B) Microbes in natural environments and their interactions
(C) Industrial use of microbes
(D) Microbes in laboratory only
2. : The first person to observe microorganisms using a microscope was:
(A) Louis Pasteur
(B) Robert Koch
(C) Antonie van Leeuwenhoek
(D) Alexander Fleming
3. : Which microorganism is mainly responsible for nitrogen fixation?
(A) Lactobacillus
(B) Rhizobium
(C) Escherichia coli
(D) Clostridium botulinum
4. : Cyanobacteria are also known as:
(A) Blue-green algae
(B) Green algae
(C) Protozoa
(D) Archaea
5. : Mycorrhizal fungi help plants mainly by improving:
(A) Photosynthesis
(B) Nitrogen fixation
(C) Water and nutrient absorption
(D) Seed germination
6. : Which of the following is a bioindicator of water pollution?
(A) Salmonella
(B) Coliform bacteria (E. coli)
(C) Bacillus subtilis
(D) Saccharomyces cerevisiae
7. : The microbial process of converting nitrates into nitrogen gas is called:
(A) Nitrification
(B) Denitrification
(C) Nitrogen fixation
(D) Ammonification
8. : The ability of microbes to degrade environmental pollutants is called:
(A) Bioaccumulation
(B) Biomagnification
(C) Bioremediation
(D) Bioaugmentation
9. : Oil spills are often cleaned using:
(A) Viruses
(B) Hydrocarbon-degrading bacteria
(C) Cyanobacteria
(D) Yeast
10. : Which microorganism is commonly used in sewage treatment?
(A) Nitrosomonas
(B) Pseudomonas
(C) Methanogens
(D) Vibrio cholerae
11. : The first antibiotic discovered, penicillin, is produced by:
(A) Streptomyces
(B) Penicillium
(C) Aspergillus
(D) Bacillus
12. : Microbes that grow at high temperatures (above 60°C) are called:
(A) Psychrophiles
(B) Mesophiles
(C) Thermophiles
(D) Halophiles
13. : Bacteria that can use oxygen if available but also grow without it are:
(A) Obligate aerobes
(B) Obligate anaerobes
(C) Facultative anaerobes
(D) Microaerophiles
14. : Which microorganisms are used in the production of biofertilizers?
(A) Rhizobium and Azotobacter
(B) E. coli and Salmonella
(C) Streptococcus and Staphylococcus
(D) Candida and Saccharomyces
15. : The microbial production of methane in anaerobic conditions is called:
(A) Denitrification
(B) Methanogenesis
(C) Photosynthesis
(D) Sulfate reduction
16. : Which bacteria are used in the production of vinegar (acetic acid)?
(A) Lactobacillus
(B) Acetobacter
(C) Bacillus
(D) Clostridium
17. : The main role of decomposer microorganisms in ecosystems is:
(A) Oxygen production
(B) Breaking down organic matter
(C) Fixing atmospheric nitrogen
(D) Causing diseases
18. : Biofilm formation on surfaces is mainly due to:
(A) Antibiotics
(B) Extracellular polymeric substances (EPS)
(C) Enzyme secretion
(D) Plasmid transfer
19. : In the sulfur cycle, the bacteria responsible for oxidizing hydrogen sulfide to sulfur are:
(A) Thiobacillus
(B) Nitrosomonas
(C) Rhizobium
(D) Clostridium
20. : Which microorganism is commonly used for ethanol production?
(A) Saccharomyces cerevisiae
(B) Rhizobium
(C) Pseudomonas
(D) Penicillium
21. : The process of using genetically engineered microbes to clean pollutants is called:
(A) Natural bioremediation
(B) Bioaugmentation
(C) Phytoremediation
(D) Genetic remediation
22. : Lichens represent a symbiotic association between:
(A) Fungi and algae/cyanobacteria
(B) Bacteria and fungi
(C) Protozoa and algae
(D) Virus and bacteria
23. : Acid mine drainage is mainly caused by the activity of:
(A) Sulfate-reducing bacteria
(B) Iron-oxidizing bacteria (Thiobacillus ferrooxidans)
(C) Nitrogen-fixing bacteria
(D) Cyanobacteria
24. : Which gas is produced by methanogenic archaea in wetlands and landfills?
(A) Carbon dioxide
(B) Methane
(C) Hydrogen sulfide
(D) Nitrous oxide
25. : The study of microorganisms in extreme environments like hot springs and deep-sea vents is called:
(A) Medical microbiology
(B) Industrial microbiology
(C) Environmental microbiology
(D) Extremophile microbiology