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 can be found in bacteria. They often contain genes for enzymes and antibiotic resistance. These genes provide the bacteria with the ability to produce enzymes for various metabolic processes and to resist the effects of antibiotics. Plasmids can be transferred between bacteria through a process called conjugation, allowing the genes they carry to spread throughout bacterial populations. 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
Glycocalix is the most important structure related to microbial attachment to cells. Glycocalix is a layer of polysaccharides and glycoproteins that surrounds the cell surface of many bacteria and other microorganisms. It plays a crucial role in microbial attachment to host cells, as it acts as an adhesive layer that allows microorganisms to adhere to surfaces, including host tissues. This attachment is essential for the colonization and establishment of infections by pathogenic microorganisms. Therefore, the glycocalix is considered the most important structure for 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 in their cell wall, while Clostridium perfringens is a gram-positive bacterium that lacks this layer. Gram-negative bugs include Vibrio cholerae, Escherichia coli, and Bordetella pertussis, as they all have a gram-negative cell wall structure.
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 die or divide. Endotoxins can be linked to Meningococcemia, are produced by gram-negative microorganisms, 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, meaning it has a thinner peptidoglycan layer in its cell wall. This allows the crystal violet stain to penetrate the cell wall and stain the bacterium purple. In contrast, Legionella pneumophila, Treponema, and Chlamydia have different cell wall structures that make them more difficult to stain using the standard Gram staining technique.
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. Neisseria gonorrhoeae is a Gram-negative diplococcus bacteria that causes the sexually transmitted infection gonorrhea. It is typically isolated on Thayer-Martin agar, which contains antibiotics to inhibit the growth of other bacteria and allow for the selective growth of Neisseria species. Pink colonies media is not a specific isolation medium for Neisseria gonorrhoeae.
7.
Which of the following diseases and bacteria are matched up incorrectly?
Correct Answer
D. Lyme disease – Yersinia pestis
Explanation
Lyme disease is caused by the bacterium Borrelia burgdorferi, not Yersinia pestis. Yersinia pestis is the bacteria responsible for causing the bubonic plague. Therefore, the match-up between Lyme disease and Yersinia pestis is incorrect.
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 is responsible for the formation of blood clots. Therefore, the statement "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, pneumonia, and epiglottis. However, it is not linked to malaria, which is caused by parasites transmitted through the bite of infected mosquitoes. Malaria is not caused by bacteria and is not associated with Haemophilus influenzae.
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. Trypanosoma gambiense is the causative agent of African trypanosomiasis, also known as sleeping sickness. The Tsetse fly acts as a vector for this parasite, transmitting it to humans and other animals through its bite. This parasite causes a range of symptoms in infected individuals, including fever, headaches, joint pain, and eventually neurological complications if left untreated. Control of the Tsetse fly population is crucial in preventing the spread of this disease.
12.
The Ixodes tick is a transmission factor for which of the following organisms?
Correct Answer
C. Babesia
Explanation
Ixodes ticks are known to be transmission factors for Babesia, a parasitic protozoan that causes babesiosis in humans and animals. These ticks are commonly found in wooded areas and can transmit the Babesia parasite through their bite. Babesiosis is a potentially serious illness that can cause symptoms such as fever, fatigue, and anemia. Therefore, the correct answer is Babesia.
13.
Chagas' disease is commonly treated with Nifurtimox and is linked to the ____ microorganism.
Correct Answer
D. Trypanosoma cruzi
Explanation
Chagas' disease, also known as American trypanosomiasis, is caused by the protozoan parasite Trypanosoma cruzi. Nifurtimox is commonly used for the treatment of Chagas' disease. Therefore, the correct answer is 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 intracellular pathogen. 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. Therefore, Chlamydiae is the only option that is not related to fungi.
15.
Which of the following is not a DNA virus?
Correct Answer
B. Calicivirus
Explanation
Calicivirus is not a DNA virus because it belongs to the family Caliciviridae, which contains single-stranded RNA viruses. DNA viruses, on the other hand, have DNA as their genetic material. Adenovirus, Papovirus, and Poxvirus are all DNA viruses.
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. Retrovirus, Orthomyxovirus, and Deltavirus are all 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 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 because it has a segmented genome consisting of three separate RNA strands. 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 certain 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.
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 typically caused by bacteria, and the most common causative agent is Escherichia coli (E. coli). Pseudomonas and Klebsiella are also known to cause UTIs. However, Haemophilus is not commonly associated with urinary tract infections.