Environmental Microbiology MCQs 25 Score: 0 Attempted: 0/25 Subscribe 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