This set of Microbiology Multiple Choice Questions & Answers (MCQs) focuses on “World of Bacteria I – Rickettsias and Chlamydias”.
1. Which of the following infect arthropods only?
Explanation: The Wolbachieae are not pathogenic for vertebrates,they infect arthropods only.
2. The Rickettsias and Chlamydias are similar in all respects.
Explanation: The Rickettsias synthesize ATP as a source of energy whereas Chlamydias cannot synthesize ATP.
3. Classical typhus fever is transmitted by which of the following arthropod?
Explanation: Classical typhus fever is caused by Rickettsia species and the arthropod vector which transmits the disease is lice.
4.”Growing epicellularly” means _______________________
a) on the surface of host cells
b) within the host cell
c) engulfing the host cell
d) damaging the cell membrane of host cell
Explanation: Growing epicellularly means growing on the surface of host cells.Rochalimaea grow epicellularly rather than in the cytoplasm or nucleus.
5. Which of the following genus of Rickettsiaceae have a high resistance to heat?
Explanation: The organisms belonging to Coxiella have an unusually high resistance to heat [may survive a temperature of 62 degree C for 30 mins], probably due to occurrence of endospore-like structures in the cells.
6. C.burnetti causes which of the following diseases?
a) Q fever
b) Trench fever
c) Rocky Mountain spotted fever
Explanation: C.burnetti is the causative agent of the Q fever, a type of pneumonia.It belongs to the family Rickettsiaceae.
7. Biting flies occur in which of the following place?
b) North America
c) South America
Explanation: Biting flies occur along the western slopes of the Andes mountains in South America. They transmit Oroya fever in humans.
8. Initial body in reproduction of Chlamydias is larger than the elementary body.
Explanation: Within the vacuole the elementary body is reorganized into a reticulate body known as initial body, which is two or three times the size of the elementary body and contains a less dense arrangement of nucleoid material.
9. Which is the most prevalent sexually transmitted disease in US?
c) lymphogranuloma venerum
d) nongonococcal urethritis
Explanation: Nongonococcal urethritis is the most prevalent sexually transmitted disease in the United States and is caused by the organisms belonging to the genus Chlamydia.
Sanfoundry Global Education & Learning Series – Microbiology.
To practice all areas of Microbiology, here is complete set of 1000+ Multiple Choice Questions and Answers.