ATI RN
microbiology chapter 1 test bank Questions
Question 1 of 5
A relationship between organisms in which the waste product of one provides nutrients for another is called
Correct Answer: D
Rationale: The correct answer is D: commensalism. In commensalism, one organism benefits while the other is neither helped nor harmed. In this relationship, the waste product of one organism serves as a nutrient source for another without affecting the first organism. Mutualism (
A) involves both organisms benefiting, competition (
B) involves a struggle for resources, and synergism (
C) involves cooperative interactions. Commensalism is the only choice where one organism benefits from the waste product of another without any impact on the producer.
Question 2 of 5
H. Influenzae type b (Hib) causes:
Correct Answer: A
Rationale: The correct answer is A: Meningitides. H. Influenzae type b (Hib) is a bacterium known to cause meningitis, a serious infection of the protective membranes covering the brain and spinal cord. Hib does not typically cause tonsillitis, urinary tract infections, or gastroenteritis. Meningitis is a life-threatening condition that requires prompt treatment, making it crucial to identify Hib as the causative agent.
Question 3 of 5
Patient with diarrhoea was admitted to the infection unit. Gram-negative curved rod-like bacteria were founded on bacterioscopic examination of faecal masses. What is the most likely disease in this patient?
Correct Answer: B
Rationale: The correct answer is B: Cholera. Cholera is caused by Gram-negative curved rod-like bacteria called Vibrio cholerae, commonly found in contaminated water or food. The characteristic symptom of cholera is profuse watery diarrhea, which matches the patient's presentation. Typhoid fever (
A) is caused by Salmonella typhi, which is not a curved rod-like bacteria. Diphtheria (
C) is caused by Corynebacterium diphtheriae, a Gram-positive bacterium, and does not typically cause diarrhea. Intestinal form of plague (
D) is caused by Yersinia pestis, which is not a curved rod-like bacteria and does not typically present with diarrhea.
Question 4 of 5
Which bacteria is the causative agent of gas gangrene?
Correct Answer: C
Rationale: The correct answer is C: Clostridium perfringens. This bacterium is the causative agent of gas gangrene due to its ability to produce gas and toxins in anaerobic conditions. Clostridium tetani causes tetanus, Clostridium botulinum causes botulism, and Bacillus anthracis causes anthrax, not gas gangrene. Clostridium perfringens stands out as the correct choice based on its specific association with gas gangrene and its pathogenic mechanisms.
Question 5 of 5
Which is the preferred mode of transmission of HIV from a mother to a child?
Correct Answer: D
Rationale: The correct answer is D: All of the above. HIV can be transmitted from mother to child during delivery through mixing of blood, during pregnancy through the placenta, and via breastmilk during lactation. Each mode of transmission carries a risk of HIV transmission to the child due to the presence of the virus in the mother's blood and bodily fluids. It is important to note that all three modes contribute to the risk of mother-to-child transmission of HIV, and preventive measures should be taken to reduce this risk.
Option A, during delivery through mixing of blood, is correct as HIV can be transmitted through exposure to infected blood during childbirth. Option B, during pregnancy through placenta, is also correct as the virus can cross the placenta and infect the fetus. Option C, via breastmilk during lactation, is correct as HIV can be present in breastmilk and transmitted to the child through breastfeeding.
Therefore, the preferred mode of transmission of HIV from a mother to a child