BIOL 271 EXAM 1 COMPLETE 200 PRACTICE QUESTIONS WITH ANSWERS & RATIONALES

BIOL 271 EXAM 1 COMPLETE 200 PRACTICE QUESTIONS WITH ANSWERS & RATIONALES 1. What is the #1 cause of bacterial diarrhea? A) Escherichia coli B) Salmonella enterica C) Campylobacter D) Shigella dysenteriae Correct Answer: C – Campylobacter is the most common bacterial cause of diarrheal illness worldwide. 2. Which of the following are the three domains of life? A) Eukarya, Archaea, Eubacteria B) Animalia, Plantae, Fungi C) Protista, Monera, Fungi D) Bacteria, Viruses, Eukarya Correct Answer: A – The three domains are Eukarya, Archaea, and Eubacteria (Bacteria). 3. What is abiogenesis? A) The origin of life from pre-existing life B) Spontaneous generation – living material comes from nonliving matter C) The creation of life through divine intervention D) The evolution of species over time Correct Answer: B – Abiogenesis refers to the now-disproven concept of spontaneous generation. 4. What does "acid-fast" refer to in microbiology? A) Ability to survive acidic environments B) Staining property where cells hold fast to dye (AFB+) C) Rapid growth in acidic media D) Resistance to acid degradation Correct Answer: B – Acid-fast organisms retain the primary dye even after acid-alcohol decolorization. 5. Which immunity is specific, induced, recognizes conserved and nonconserved regions, and produces memory? A) Innate immunity B) Acquired/adapted immunity C) Passive immunity D) Natural immunity Correct Answer: B – Acquired immunity has specificity, inducibility, recognition of diverse antigens, and memory. 6. What are algae? A) Photosynthetic prokaryotes that live in terrestrial environments B) Photosynthetic eukaryotes that live in aqueous environments C) Non-photosynthetic eukaryotes found in soil D) Chemosynthetic bacteria found in deep-sea vents Correct Answer: B – Algae are eukaryotic photosynthetic organisms primarily found in aquatic habitats. 7. What is the measurement of an angstrom? A) 10^-9 m B) 10^-10 m C) 10^-8 m D) 10^-12 m Correct Answer: B – An angstrom (Å) is equal to 10^-10 meters. 8. What is another name for the axial filament? A) Periplasmic flagellum B) Endoflagellum C) Fimbria D) Pilus Correct Answer: B – The axial filament is also called the endoflagellum. 9. What is another name for differential interference microscopy? A) Brightfield B) Phase-contrast C) Nomarski D) Darkfield Correct Answer: C – Nomarski is another name for differential interference contrast microscopy. 10. Who discovered animalcules and reported them to the Royal Society but failed to share his microscopy expertise? A) Robert Hooke B) Louis Pasteur C) Anthony van Leeuwenhoek D) Ferdinand Cohn Correct Answer: C – Leeuwenhoek discovered animalcules but did not reveal his microscopy methods. 11. What is an antigen? A) A substance that inhibits immune responses B) Any substance capable of inducing an immune response C) A type of white blood cell D) A protein that destroys pathogens Correct Answer: B – Antigens are molecules that trigger specific immune responses. 12. What are the antigen receptors on B cells called? A) TCR B) Immunoglobulin/antibody C) MHC molecules D) Cytokines Correct Answer: B – B cells use immunoglobulins (antibodies) as antigen receptors. 13. What are the antigen receptors on T cells called? A) Immunoglobulin B) TCR (T-cell receptor) C) CD markers D) Complement proteins Correct Answer: B – T cells express T-cell receptors (TCR) for antigen recognition. 14. Which type of microbiology includes food, environmental, industrial, pharmaceutical, and recombinant DNA technology? A) Pure microbiology B) Applied microbiology C) Medical microbiology D) Theoretical microbiology Correct Answer: B – Applied microbiology utilizes microorganisms in various practical fields. 15. Which domain includes prokaryotes living in extreme environments? A) Eukarya B) Eubacteria C) Archaea D) Viruses Correct Answer: C – Archaea are known for thriving in extreme habitats. 16. What are arthrobodies? A) Arthropod vectors such as mosquitoes, fleas, and ticks B) Antibodies produced against arthropods C) Bacterial structures D) Fungal spores Correct Answer: A – Arthrobodies refer to arthropod vectors that transmit diseases. 17. What is the term for a bacterium with no flagellum? A) Monotrichous B) Lophotrichous C) Atrichous D) Peritrichous Correct Answer: C – Atrichous means lacking flagella. 18. How does the axial filament provide motility? A) By rotating like a propeller B) By flexing back and forth like a slinky in the cell walls of spirochetes C) By gliding on a slime layer D) By contracting and expanding Correct Answer: B – Axial filaments in spirochetes flex and rotate to produce corkscrew-like movement.