Nokea
Complex communities of microorganisms on surfaces are called
- A. colonies
- B. biofilms
- C. biospheres
- D. flora
Correct Answer: B
Rationale: The correct answer is B: biofilms. Biofilms refer to complex communities of microorganisms that adhere to surfaces. They are characterized by a protective matrix that allows the microorganisms to communicate and cooperate. Colonies (A) typically refer to groups of a single species, not diverse communities. Biospheres (C) refer to the regions of the Earth where life exists, not specific microbial communities. Flora (D) generally refers to the plant life in a particular region, not microbial communities on surfaces.
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Growth of bacteria is a result of:
- A. Air consumption
- B. Water adsorption
- C. Enzyme production
- D. Radio isotopes
Correct Answer: B
Rationale: The growth of bacteria is a result of water adsorption because water is essential for various metabolic processes within the bacterial cells, such as nutrient uptake, energy production, and waste removal. Water serves as a medium for chemical reactions to occur and provides structural support to the bacteria. Without sufficient water, bacteria cannot thrive and reproduce.
A: Air consumption is incorrect because while bacteria may require oxygen for respiration, it is not the primary factor for their growth.
C: Enzyme production is incorrect because enzymes are important for various cellular functions but do not directly influence bacterial growth.
D: Radio isotopes are incorrect as they are not essential for bacterial growth and can even be harmful to bacterial cells.
For tuberculosis prevention the newborns got an injection of a vaccine. What vaccine was used?
- A. BCG
- B. Mantoux
- C. DTaP vaccine
- D. Anatoxin
Correct Answer: A
Rationale: The correct answer is A: BCG. BCG vaccine is commonly used for tuberculosis prevention because it provides immunity against Mycobacterium tuberculosis. Mantoux is a test, not a vaccine. DTaP vaccine is for diphtheria, tetanus, and pertussis, not tuberculosis. Anatoxin is a type of toxoid vaccine, not used for tuberculosis prevention. BCG vaccine has been shown to be effective in preventing severe forms of tuberculosis in infants, making it the appropriate choice in this scenario.
Salmonellosis is caused by:
- A. Salmonella typhi
- B. Salmonella enteritidis
- C. Shigella flexneri
- D. None of the above
Correct Answer: B
Rationale: The correct answer is B: Salmonella enteritidis. Salmonellosis is typically caused by Salmonella species, with Salmonella enteritidis being one of the common culprits. Salmonella typhi causes typhoid fever, not salmonellosis. Shigella flexneri is responsible for causing shigellosis, a different bacterial infection. Choosing "None of the above" is incorrect as Salmonella enteritidis is a known cause of salmonellosis.
A fecal sample cultured on Endo agar revealed colorless colonies. The bacteria were Gram-negative rods and lactose non-fermenters. What microorganism is most likely?
- A. Salmonella
- B. Escherichia coli
- C. Shigella
- D. Proteus
Correct Answer: C
Rationale: The correct answer is Shigella (Choice C) because it matches the description of being Gram-negative rods and lactose non-fermenters. Shigella is a non-lactose fermenting, Gram-negative rod that typically produces colorless colonies on Endo agar. Salmonella (Choice A) and Escherichia coli (Choice B) are both lactose fermenters and would produce pink colonies on Endo agar. Proteus (Choice D) is also a lactose fermenter and would appear pink on Endo agar. Therefore, based on the characteristics provided, Shigella is the most likely microorganism in this scenario.
Which bacteria are responsible for causing the plague?
- A. Escherichia coli
- B. Yersinia pestis
- C. Clostridium difficile
- D. Staphylococcus aureus
Correct Answer: B
Rationale: The correct answer is B: Yersinia pestis. Yersinia pestis is the bacterium responsible for causing the plague, specifically the bubonic plague. It is transmitted through fleas and rodents. Escherichia coli (A) is a common gut bacterium, Clostridium difficile (C) causes antibiotic-associated diarrhea, and Staphylococcus aureus (D) is associated with skin infections, but they are not responsible for causing the plague.