McGraw Hill Microbiology Test Bank

McGraw Hill Microbiology Test Bank Related

Review McGraw Hill Microbiology Test Bank related questions and content

Sanitary assessment of a pond, where the children from a recreation summer camp take their swims, detected there oval cysts 50-60 micron in diameter, with 2 nuclei visible in their cytoplasm (macronucleus and micronucleus). What protozoa do these cysts belong to?

  • A. Toxoplasma
  • B. Amoeba
  • C. Balantidium
  • D. Lamblia
Correct Answer: D

Rationale: The correct answer is D: Lamblia. The cysts described match the characteristics of Giardia lamblia, a protozoan parasite. Giardia cysts are oval-shaped, 50-60 microns in diameter, and contain 2 nuclei (macronucleus and micronucleus). Giardia is commonly found in contaminated water sources and can cause gastrointestinal illness in humans.

Incorrect choices:
A: Toxoplasma - Toxoplasma gondii is a parasite that causes toxoplasmosis, transmitted through ingestion of contaminated food or water, but its cysts do not match the description given in the question.
B: Amoeba - Amoebas are single-celled organisms, but they do not typically form cysts with visible nuclei as described.
C: Balantidium - Balantidium coli is a ciliated protozoan that can cause dysentery in humans, but its cysts do not

You may also like to solve these questions

Giardiasis is a waterborne gastrointestinal disease caused by Giardia intestinalis, which is a:

  • A. protozoan
  • B. bacterium
  • C. fungus
  • D. virus
Correct Answer: A

Rationale: Step 1: Giardiasis is caused by Giardia intestinalis, which is a well-known protozoan parasite.
Step 2: Protozoans are single-celled eukaryotic organisms commonly found in water sources.
Step 3: Giardia intestinalis infects the intestine, causing symptoms like diarrhea and abdominal cramps.
Step 4: Bacteria (Choice B) are prokaryotic organisms, different from protozoans.
Step 5: Fungi (Choice C) are also eukaryotic but are not responsible for causing Giardiasis.
Step 6: Viruses (Choice D) are not cellular and cannot independently cause Giardiasis.
In summary, the correct answer is A (protozoan) because Giardia intestinalis is a protozoan parasite specifically known to cause Giardiasis, while the other choices (Bacterium, Fungus, Virus) do not match the characteristics of the

The polymerase chain reaction CAN NOT be applied:

  • A. To prove latent infection
  • B. For rapid diagnosis of infectious diseases
  • C. To determine the antibiotic susceptibility of microorganisms
  • D. To demonstrate DNA and RNA molecule
Correct Answer: C

Rationale: The correct answer is C: To determine the antibiotic susceptibility of microorganisms. PCR is not suitable for determining antibiotic susceptibility as it is a technique used to amplify DNA/RNA, not to test for antibiotic resistance. To prove latent infection (A), PCR can be used to detect low levels of pathogens. For rapid diagnosis of infectious diseases (B), PCR is commonly used due to its sensitivity and specificity. To demonstrate DNA and RNA molecules (D), PCR is ideal as it can amplify and detect specific sequences. Therefore, choice C is incorrect as PCR is not designed for determining antibiotic susceptibility.

Specimen of a patient's sputum was stained with the following dyes and reagents: Ziehl's solution, methylene blue solution, 5% solutoin of sulfuric acid. What staining method was applied?

  • A. Ziehl-Neelsen
  • B. Burri's
  • C. Gram's
  • D. Peshkov's
Correct Answer: A

Rationale: The correct answer is A: Ziehl-Neelsen staining method was applied.
1. Ziehl's solution is used as a primary stain in Ziehl-Neelsen staining for acid-fast organisms like Mycobacterium tuberculosis.
2. Sulfuric acid is used as a decolorizer to remove excess stain.
3. Methylene blue is not part of the Ziehl-Neelsen staining method.
4. Burri's, Gram's, and Peshkov's staining methods are not used for acid-fast staining.

Which of the following microorganisms are acid-fast?

  • A. Streptococcus pyogenes
  • B. Mycobacterium tuberculosis
  • C. Clostridium perfringens
  • D. Bacillus subtilis
Correct Answer: B

Rationale: The correct answer is B: Mycobacterium tuberculosis. Acid-fast bacteria have a unique cell wall component called mycolic acid, making them resistant to decolorization by acid-alcohol during staining. Mycobacterium tuberculosis is acid-fast, as it retains the stain due to its high lipid content. Streptococcus pyogenes (A), Clostridium perfringens (C), and Bacillus subtilis (D) do not possess mycolic acid in their cell walls, so they are not acid-fast.

What is the function of bacterial flagella?

  • A. Protein synthesis
  • B. Motility
  • C. Adhesion to surfaces
  • D. DNA replication
Correct Answer: B

Rationale: The correct answer is B: Motility. Bacterial flagella function in providing motility to bacteria, allowing them to move towards nutrients or away from harmful substances. Flagella are long, whip-like appendages that rotate to propel the bacteria through their environment.
Incorrect choices:
A: Protein synthesis - Bacterial flagella are not involved in protein synthesis.
C: Adhesion to surfaces - While some bacteria use flagella for attachment, their main function is not adhesion.
D: DNA replication - Flagella do not play a role in DNA replication, which occurs in the bacterial cell's nucleus.

Copyright © 2025 Nokea. All rights reserved.