Nokea
Which structure in bacteria allows them to exchange genetic material during conjugation?
- A. Pili
- B. Flagella
- C. Capsule
- D. Ribosomes
Correct Answer: A
Rationale: Pili in bacteria are responsible for conjugation, allowing the transfer of genetic material between cells. They form a bridge between donor and recipient cells, facilitating the exchange of DNA. Flagella are for movement, capsules for protection, and ribosomes for protein synthesis. Pili is the only structure directly involved in genetic material exchange.
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Bacterial infections of the female reproductive system include:
- A. vaginitis, toxic shock syndrome, endometritis, and salpingitis
- B. nephritis, endometritis, vaginitis, and pelvic inflammatory disease
- C. toxic shock syndrome, nephritis, endometritis, and cystitis
- D. endometritis, vaginitis, cystitis, and toxic shock syndrome
Correct Answer: A
Rationale: Rationale:
1. Vaginitis is a common bacterial infection in the female reproductive system.
2. Toxic shock syndrome can be caused by certain bacterial infections.
3. Endometritis is inflammation of the endometrium often due to bacterial infections.
4. Salpingitis is inflammation of the fallopian tubes, commonly caused by bacteria.
Summary:
- Choice B: Nephritis is a kidney infection, not related to female reproductive system infections.
- Choice C: Nephritis and cystitis are not specific to the female reproductive system.
- Choice D: Cystitis is a bladder infection, not typically considered part of female reproductive system infections.
A man uses dentures. The dentist has noticed mucosal lecions with a white coating in his oral cavity. Microscopy of the coating detected large oval Gram-positive cells. What microorganisms have caused stomatitis in the patient?
- A. Yeast-like fungi of Candida genus
- B. Actinomycetes
- C. Streptococci
- D. Oral spirochetes
Correct Answer: A
Rationale: The correct answer is A: Yeast-like fungi of Candida genus. Candida is a common cause of oral thrush/stomatitis, characterized by mucosal lesions with white coating. The presence of large oval Gram-positive cells is indicative of Candida species. Actinomycetes (B) are filamentous bacteria and not oval Gram-positive cells. Streptococci (C) are spherical bacteria, not oval, and are not commonly associated with stomatitis. Oral spirochetes (D) are spiral-shaped bacteria and not oval Gram-positive cells typically seen in Candida infections. Thus, A is the correct choice based on the characteristic morphology and clinical presentation.
Which bacteria is a common cause of urinary tract infections (UTIs)?
- A. Clostridium tetani
- B. Escherichia coli
- C. Mycobacterium leprae
- D. Bacillus anthracis
Correct Answer: B
Rationale: The correct answer is B: Escherichia coli. E. coli is the most common cause of UTIs due to its ability to colonize the urinary tract. It possesses adhesive factors that enable it to attach to the bladder and cause infection. Clostridium tetani causes tetanus, Mycobacterium leprae causes leprosy, and Bacillus anthracis causes anthrax, none of which are typically associated with UTIs. E. coli's prevalence in the gut and its pathogenic mechanisms make it the leading cause of UTIs.
Which of the following bacteria is associated with Lyme disease?
- A. Borrelia burgdorferi
- B. Clostridium botulinum
- C. Escherichia coli
- D. Streptococcus pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Borrelia burgdorferi. This bacterium is associated with Lyme disease, a tick-borne illness. Borrelia burgdorferi is transmitted to humans through the bite of infected black-legged ticks. It causes a range of symptoms, including fever, rash, joint pain, and neurological problems.
Summary:
B: Clostridium botulinum is associated with botulism, a serious illness caused by a toxin produced by this bacterium.
C: Escherichia coli is a common bacterium found in the intestines of humans and animals, some strains can cause food poisoning.
D: Streptococcus pneumoniae is a bacterium that can cause pneumonia and other respiratory infections, but not Lyme disease.
Which of the following bacteria is responsible for causing the disease known as leprosy?
- A. Mycobacterium leprae
- B. Neisseria gonorrhoeae
- C. Escherichia coli
- D. Staphylococcus aureus
Correct Answer: A
Rationale: Step-by-step rationale:
1. Mycobacterium leprae is the correct answer because it is the bacterium responsible for causing leprosy.
2. Neisseria gonorrhoeae causes gonorrhea, not leprosy.
3. Escherichia coli is associated with gastrointestinal infections, not leprosy.
4. Staphylococcus aureus causes various skin infections, but not leprosy.
In summary, Mycobacterium leprae is the correct choice because it is the specific bacterium known to cause leprosy, while the other options are associated with different diseases.