1.
Which of the following structures contains genes for enzymes and antibiotic resistance?
Correct Answer
A. Plasmid
Explanation
Plasmids are small, circular DNA molecules that are separate from the chromosomal DNA. They are commonly found in bacteria and contain genes for enzymes and antibiotic resistance. These genes allow bacteria to produce enzymes that aid in various metabolic processes and also to resist the effects of antibiotics. Therefore, plasmids are the structures that contain genes for enzymes and antibiotic resistance.
2.
Which of the following is the most important structure related to microbial attachment to cells?
Correct Answer
D. Glycocalix
Explanation
The glycocalix is a gelatinous layer that surrounds the cell membrane of some bacteria. It plays a crucial role in microbial attachment to cells as it allows bacteria to adhere to surfaces and form biofilms. This structure provides protection against environmental stresses and helps bacteria to resist the immune system. It also facilitates the exchange of nutrients and signals between bacteria and their host cells. Therefore, the glycocalix is considered the most important structure related to microbial attachment to cells.
3.
Which of the following is not a gram-negative bug?
Correct Answer
A. Clostridium perfringens
Explanation
Clostridium perfringens is not a gram-negative bug. Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane, while Clostridium perfringens is a gram-positive bacterium that lacks the outer membrane.
4.
Which of the following is not true related to endotoxins?
Correct Answer
A. Endotoxins are secreted from cells.
Explanation
Endotoxins are not secreted from cells. They are a component of the outer membrane of gram-negative bacteria and are released when the bacteria are destroyed or undergo lysis. They can be linked to Meningococcemia and can cause fever.
5.
Which of the following microorganisms stain well?
Correct Answer
A. Escherichia coli
Explanation
Escherichia coli stains well because it is a gram-negative bacterium. Gram-negative bacteria have a thinner peptidoglycan layer in their cell walls, which allows the crystal violet stain to wash out more easily. This makes it easier for the counterstain, safranin, to be taken up and for the bacteria to appear pink under a microscope. Legionella pneumophila, Treponema, and Chlamydia are all gram-negative bacteria as well, but they may not stain as well due to variations in their cell wall composition or other factors.
6.
Which of the following microorganisms are not matched correctly with the appropriate isolation media?
Correct Answer
B. Neisseria gonorrhoeae – Pink colonies media
Explanation
The correct answer is Neisseria gonorrhoeae - Pink colonies media. This is because Neisseria gonorrhoeae is typically isolated on selective media such as Thayer-Martin agar or Modified Thayer-Martin agar, which contains antibiotics to inhibit the growth of other bacteria. Pink colonies media does not specifically select for Neisseria gonorrhoeae and is not the appropriate isolation media for this microorganism.
7.
Which of the following diseases and bacteria are matched up incorrectly?
Correct Answer
D. Lyme disease – Yersinia pestis
Explanation
The given answer is correct because Lyme disease is caused by the bacteria Borrelia burgdorferi, not Yersinia pestis. Yersinia pestis is the bacteria responsible for causing bubonic plague.
8.
Which of the following diseases and bacteria are matched up incorrectly?
Correct Answer
D. Yersinia enterocolitica – Diptheria
9.
Which of the following is not true concerning Staphylococcus aureus?
Correct Answer
D. S. aureus does not make coagulase
Explanation
Coagulase is an enzyme produced by Staphylococcus aureus that causes the formation of blood clots. This ability is one of the characteristics that distinguish S. aureus from other staphylococci. Therefore, the statement that S. aureus does not make coagulase is not true.
10.
Which of the following signs and symptoms is not linked to Haemophilus influenzae?
Correct Answer
C. Malaria
Explanation
Haemophilus influenzae is a bacterium that can cause various infections, including otitis media (middle ear infection), pneumonia, and epiglottitis (inflammation of the epiglottis). However, malaria is a parasitic infection caused by Plasmodium parasites and is not linked to Haemophilus influenzae. Therefore, the correct answer is "Malaria."
11.
The Tsetse fly is a transmission factor for which of the following organisms?
Correct Answer
B. Trypanosoma gambiense
Explanation
The Tsetse fly is a transmission factor for Trypanosoma gambiense. This means that the Tsetse fly can carry and transmit Trypanosoma gambiense, a parasite that causes African trypanosomiasis, also known as sleeping sickness.
12.
The Ixodes tick is a transmission factor for which of the following organisms?
Correct Answer
C. Babesia
Explanation
The Ixodes tick is a transmission factor for Babesia. Babesia is a parasitic protozoan that infects red blood cells and causes a disease called babesiosis. The Ixodes tick is known to be a vector for transmitting Babesia to humans and animals. This tick species is commonly found in regions where babesiosis is endemic, such as certain parts of the United States and Europe.
13.
Chagas' disease is commonly treated with Nifurtimox and is linked to the ____ microorganism.
Correct Answer
D. Trypanosoma cruzi
Explanation
Chagas' disease is commonly treated with Nifurtimox, which suggests that the disease is caused by the microorganism Trypanosoma cruzi.
14.
Which of the following is not fungal related?
Correct Answer
D. Chlamydiae
Explanation
Chlamydiae is not fungal related because it is a type of bacteria, specifically an obligate intracellular parasite. It causes a number of diseases in humans and animals, such as chlamydia, which is a sexually transmitted infection. In contrast, Cryptococcus neoformans and Candida albicans are both types of fungi that can cause infections in humans. Tinea nigra is a superficial fungal infection of the skin.
15.
Which of the following is not a DNA virus?
Correct Answer
B. Calicivirus
Explanation
Calicivirus is not a DNA virus. Adenovirus, Papovirus, and Poxvirus are all DNA viruses. Calicivirus, on the other hand, is an RNA virus. RNA viruses have RNA as their genetic material instead of DNA.
16.
Which of the following is not a RNA virus?
Correct Answer
D. Herpesvirus
Explanation
Herpesvirus is not a RNA virus because it belongs to the family Herpesviridae which contains double-stranded DNA as its genetic material. RNA viruses, on the other hand, have RNA as their genetic material. Reovirus, Orthomyxovirus, and Deltavirus are all examples of RNA viruses.
17.
Which of the following viruses is not a double strand linear DNA virus?
Correct Answer
B. Papovavirus
Explanation
Papovavirus is not a double strand linear DNA virus. Poxvirus, Adenovirus, and Herpesvirus are all examples of double strand linear DNA viruses.
18.
Which of the following viruses is not a single strand linear RNA virus?
Correct Answer
C. Bunyavirus
Explanation
Bunyavirus is not a single strand linear RNA virus. It is a segmented RNA virus, meaning that its genome is composed of multiple separate RNA segments. Togavirus, Retrovirus, and Picornavirus are all single strand linear RNA viruses.
19.
The Tzanck test is not used on which of the following viruses?
Correct Answer
C. HHV-8
Explanation
The Tzanck test is a diagnostic test used to identify viral infections by examining cells from a skin lesion under a microscope. It is commonly used for viruses like VZV (Varicella-zoster virus), HSV-1 (Herpes simplex virus type 1), and HSV-2 (Herpes simplex virus type 2). However, HHV-8 (Human herpesvirus 8) is not typically tested using the Tzanck test. Therefore, HHV-8 is the correct answer as it is not included in the list of viruses that the Tzanck test is used for.
20.
Which of the following microorganisms has not been linked to UTI's?
Correct Answer
D. HaemopHilus
Explanation
Haemophilus has not been linked to UTIs. UTIs are commonly caused by bacteria such as E. coli, Pseudomonas, and Klebsiella. Haemophilus is typically associated with respiratory infections rather than urinary tract infections.