WGU C453 Clinical Microbiology OA ACTUAL EXAM 2025/2026 COMPLETE QUESTIONS WITH CORRECT DETAILED ANSWERS || 100% GUARANTEED PASS RECENT VERSION

WGU C453 Clinical Microbiology OA ACTUAL EXAM 2025/2026 COMPLETE QUESTIONS WITH CORRECT DETAILED ANSWERS || 100% GUARANTEED PASS RECENT VERSION 1. Bacteria - ANSWER Single-celled organism that do not have a cell nucleus and the membrane-enclosed intracellular structures found in most other cells (Prokaryotic cell). 2. Gram-positive Bacteria - ANSWER Thick layer of peptidoglycan (20 80nm across). The peptidoglycan layer is closely attached to the outer surface of the cell membrane. Retains crystal violet stains. Lack an outer membrane and a periplasmic space. 3. Gram-negative Bacteria - ANSWER Cell wall is thinner, but more complex. Only 10-20% peptidoglycan. Contains an outer membrane, leaving a very narrow periplasmic space. Does not retain crystal violet stain because of large quantities of lipoproteins and lipopolysaccharides (endotoxin). 4. Acid-fast Bacteria - ANSWER Cell wall is thick, but consists of 60% lipids. Lipids make acid-fast organisms impermeable to most other stains and protect them from acids and alkalis. Stain as gram-positive. Grow slowly because the lipids impeded entry of nutrients. 5. Endotoxin - ANSWER Lipopolysaccharide (LPS). Part of the outer membrane of the cell wall of gram-negative bacteria. It can cause fever and dilates blood vessels- causing BP to drop. Bacteria typically release this when they are dying, so killing them increases the concentration of this toxic substance. Antibiotics given late in the infection can cause worsening of symptoms or even death. 6. Wall-deficient Bacteria - ANSWER Protected by a strengthened cell membrane that contains sterols. Example: mycobacterium paratuberculosis with Crohn's disease- a chronic disorder of the intestine. 7. Coccus - ANSWER Sphere shaped bacteria 8. Coccobacillus - ANSWER Short rod shaped bacteria (between cocci and bacilli) 9. Vibrio - ANSWER Comma shaped bacteria 10. Bacillus - ANSWER Rod shaped bacteria 11. Spirillum - ANSWER Rigid, wavy shaped bacteria 12. Spirochete - ANSWER Corkscrew shape bacteria 13. Function of cell membrane - ANSWER To regulate movement of materials into and out of the cell by transport mechanisms. It synthesizes cell wall components, assists with DNA replication, secretes proteins, carries on respiration, and captures energy as ATP. 14. Function of the cell wall - ANSWER Helps maintain the characteristic shape of the cell and prevents the cell from bursting when fluids flow into the cell by osmosis. Lies outside the cell membrane. 15. Peptidoglycan - ANSWER Single most important component of the bacterial cell wall. 16. Autoclave - ANSWER Piece of equipment used to sterilize articles by way of steam under pressure and effectively destroys endospores 17. Ultraviolet light - ANSWER form of radiation which is not visible to the human eye, commonly used in animal labs to limit microorganisms 18. Cross-resistance - ANSWER Is resistance to two or more similar antimicrobial agents via a common mechanism. Example: Beta lactamase. 19. Sterilization - ANSWER Complete destruction of all forms of microbial life 20. Disinfection - ANSWER Directly targets the removal of all pathogens, not necessarily all microorganisms. 21. Sanitization - ANSWER The removal of microbes from eating utensils and food preparation areas 22. Bacteriostatic agent - ANSWER An agent that inhibits the growth of bacteria. 23. Viricide - ANSWER An agent that inactivates viruses. 24. Germicide - ANSWER An agent capable of killing microbes rapidly. Some agents kill microorganisms, some only inhibit the growth. 25. Bactericide - ANSWER An agent that kills bacteria- most do not kill spores. 26. Fungicide - ANSWER An agent that kills fungi 27. Sporocide - ANSWER An agent that kills bacteria endospores or fungal spores. 28. Antiseptic - ANSWER are applied to living tissue 29. Detergents - ANSWER Typically applied to inanimate objects. Uses: Hand washing (soap), laundering, sanitizing kitchen and dairy equipment. 30. Phenols - ANSWER Denature proteins, inactivates enzymes, & disrupt membranes. Disinfect surfaces and destroy discarded cultures. Surgical scrub. 31. Alcohols - ANSWER Denature proteins when mixed with water. Used to disinfect skin and can be used in aerosols 32. Acids - ANSWER Lower pH and denature proteins. Uses: Food preservation 33. Alkylating Agents - ANSWER Disrupt structure of proteins and nucleic acids. Uses: Disinfect and sterilize inanimate objects that would be harmed by high temperatures. Formaldehyde. 34. Dyes - ANSWER May interfere with replication or block cell wall synthesis. Uses: Clean wounds. Crystal Violet used to treat some protozoan and fungal infections. 35. Oxidizing Agents - ANSWER Disrupt disulfide bonds. Uses: clean puncture wounds, disinfect instruments. 36. Halogens - ANSWER Chlorine- used in water. Iodine- used on skin. 37. Heavy Metals - ANSWER Denature proteins. Example: Silver nitrite, Mercury, Copper 38. Alkalis - ANSWER Raise pH and denature proteins. Found in soaps. 39. Physical Antimicrobial Agents - ANSWER Filtration, irradiation, autoclave (moist heat), UV light, Pasteurization. Filtration (filtration membranes) Irradiation Autoclave(moist heat) Ultraviolet Light Pasteurization 40. How does isoniazid exert its action? - ANSWER It interferes with the synthesis of mycolic acid. 41. How does chloramphenicol exert its action? - ANSWER It inhibits protein synthesis. 42. What is the target of the antiviral drug azidothymidine, or AZT? - ANSWER Viral reverse transcriptase 43. What is the target of the antihelminthic agent niclosamide? - ANSWER Carbohydrate metabolism 44. Which mechanism would result in resistance to tetracyclines? - ANSWER Alteration of membrane permeability 45. Which mechanism of resistance would result in destroying penicillins? - ANSWER Development of beta-lactamase 46. The doctor prescribes amoxicillin as well as clavulanic acid. Why might this course of treatment be successful? - ANSWER Clavulanic acid acts synergistically with amoxicillin by binding to an enzyme that can inactivate amoxicillin. 47. Which process uses an autoclave to remove all microorganisms from medical instruments? - ANSWER Sterilization 48. Which treatment is used to decrease microbial counts on eating and drinking utensils in restaurants? - ANSWER Sanitization 49. Which method describes the removal or destruction of all microorganisms in or on an object? - ANSWER Sterilization 50. Which antimicrobial agent mainly inhibits organism growth? - ANSWER Bacteriostatic 51. Which two substances are found in some food products as preservatives? - ANSWER Halogens and phenols 52. Which substance can be effective in inactivating viruses? - ANSWER Detergents 53. Which type of microorganism causes ringworm? - ANSWER Fungus 54. Which etiological agent causes warts and is a leading cause of cervical cancer? - ANSWER Human papillomavirus 55. Which disease affecting females has symptoms that include intense itching and a copious white discharge? - ANSWER Trichomoniasis 56. Which disease is caused by Haemophilus ducreyi? - ANSWER Chancroid 57. Which lower respiratory disease is spread by soil and water? - ANSWER Legionnaires' disease 58. Which lower respiratory pathogen is characterized by mycolic acid in its cell membrane and growth within macrophages and can be acquired by inhaling aerosolized drops? - ANSWER Mycobacterium tuberculosis 59. Which helminthic disease is passed when a mosquito bites a host, allowing worm larvae to enter the blood, and can lead to elephantiasis of the limbs and scrotum? - ANSWER Filariasis 60. Which protozoan systemic disease is characterized by mild lymph node inflammation, can lead to congenital defects in the fetus, and is acquired through contact with domestic cats? - ANSWER Toxoplasmosis 61. Which preventative treatment should be used to protect against human papillomavirus (HPV) strains 16 and 18? - ANSWER Gardasil 62. Which dental disease is characterized by the chemical removal of enamel and can eventually cause abscesses in the bone of supporting teeth? - ANSWER Dental caries 63. What is a symptom of mumps? - ANSWER Swelling of the salivary glands 64. Which nerve disease presents with high fever, back pain, muscle spasms, and sometimes paralysis and is transmitted by the fecal-oral route? - ANSWER Poliomyelitis 65. Which nervous system disease is spread by improperly processed milk, cheese, and meats? - ANSWER Listeriosis 66. It is determined that a bacterial sample grows robustly in low, moderate, and high concentrations of salt. 67. What is most likely true about this organism? - ANSWER It is halotolerant. 68. What is the additional molecule contained in the cell walls of Gram-positive organisms that plays a role in the attachment of bacteriophages? - ANSWER Teichoic acid 69. In which type of bacteria is the periplasmic space between the cell membranes most easily observable? - ANSWER Gram-negative 70. What connects bacterial cells during the exchange of genetic material? - ANSWER Pilus 71. Which component helps bacterial cells attach to host blood cells and causes clumping? - ANSWER Pilus 72. Which fungal structure can form long, extended filaments, and can regrow from fragments that have broken off allowing some fungi to survive and spread disease rapidly within a single host? - ANSWER Hypha 73. What is produced by bacteria such as Helicobacter pylori to survive the extremely low pH environment of the human stomach? - ANSWER Urease 74. Which virus subgroup requires the enzyme reverse transcriptase for replication of its nucleic acid? - ANSWER Single-stranded RNA virus 75. Which type of organism causes illnesses such as amoebic dysentery and malaria? - ANSWER Protozoa 76. Which parasite's embryo enters the human intestines through the ingestion of undercooked cow's meat? - ANSWER tapeworm