Nokea
Family Retroviridae
- A. are helical enveloped viruses
- B. Their capsid consists of two copies o ssRNA (-)
- C. are helical, non-enveloped viruses
- D. are with complex type of symmetry
Correct Answer: B
Rationale: The correct answer is B because retroviruses, including those in the Family Retroviridae, have a capsid consisting of two copies of single-stranded RNA (ssRNA). This is a defining characteristic of retroviruses, which use reverse transcriptase to convert their ssRNA into DNA. This DNA is then integrated into the host cell's genome. Choices A, C, and D are incorrect because Family Retroviridae viruses are not helical non-enveloped viruses (C), they are not helical enveloped viruses (A), and they do not have a complex type of symmetry (D).
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Bacteria capable of growing at low temperatures are called:
- A. mesophiles
- B. thermophiles
- C. psychrophiles
- D. halophiles
Correct Answer: C
Rationale: The correct answer is C: psychrophiles. Psychrophiles are bacteria that can grow at low temperatures, typically below 20°C. This is because they have adapted to survive and thrive in cold environments. Mesophiles (A) grow best at moderate temperatures, thermophiles (B) thrive in high temperatures, and halophiles (D) prefer high salt concentrations. Psychrophiles are specifically adapted to cold temperatures, making them the correct choice in this scenario.
Bacterial infections of the female reproductive system include:
- A. vaginitis, toxic shock syndrome, endometritis, and salpingitis
- B. nephritis, endometritis, vaginitis, and pelvic inflammatory disease
- C. toxic shock syndrome, nephritis, endometritis, and cystitis
- D. endometritis, vaginitis, cystitis, and toxic shock syndrome
Correct Answer: A
Rationale: Rationale:
1. Vaginitis is a common bacterial infection in the female reproductive system.
2. Toxic shock syndrome can be caused by certain bacterial infections.
3. Endometritis is inflammation of the endometrium often due to bacterial infections.
4. Salpingitis is inflammation of the fallopian tubes, commonly caused by bacteria.
Summary:
- Choice B: Nephritis is a kidney infection, not related to female reproductive system infections.
- Choice C: Nephritis and cystitis are not specific to the female reproductive system.
- Choice D: Cystitis is a bladder infection, not typically considered part of female reproductive system infections.
The dynamic balance of the species in the normal microflora is known as
- A. dysbiosis
- B. eukaryota
- C. dispersion
- D. eubiosis
Correct Answer: D
Rationale: The correct answer is D: eubiosis. Eubiosis refers to a state of balance and harmony among the species in the normal microflora. This term signifies a healthy and stable microbial community. Dysbiosis (A) is the opposite, indicating an imbalance or disruption in the microflora. Eukaryota (B) refers to organisms with cells containing a nucleus, not specifically related to the balance of microflora. Dispersion (C) refers to the spreading or distribution of microorganisms, not specifically related to their balance. In summary, eubiosis best describes the dynamic balance of species in the normal microflora, making it the correct choice.
A patient complains of acute spastic abdominal pain, frequent urge to defecate, liquid bloody feces with mucus. Laboratory analysis of fecal smear revealed inconstant in shape organisms with erythrocyte. What is the most likely diagnosis?
- A. Amebiasis.
- B. Lambliasis.
- C. Schistosomiasis.
- D. Intestinal trichomoniasis.
Correct Answer: A
Rationale: The correct answer is A: Amebiasis. Amebiasis is caused by the parasite Entamoeba histolytica, presenting with symptoms like acute abdominal pain, bloody diarrhea with mucus, and inconstant shape organisms seen in fecal smear. The presence of erythrocytes supports the diagnosis due to the parasite's ability to invade intestinal mucosa causing bleeding. Choice B (Lambliasis) presents with different symptoms like steatorrhea and fatigue. Choice C (Schistosomiasis) is mainly associated with liver and urinary symptoms. Choice D (Intestinal trichomoniasis) commonly presents with watery diarrhea and does not typically cause bloody stools. Therefore, based on the patient's symptoms and fecal smear findings, Amebiasis is the most likely diagnosis.
Which of the following is a characteristic feature of Gram-positive bacteria?
- A. Outer membrane
- B. Thin peptidoglycan layer
- C. Thick peptidoglycan layer
- D. Presence of LPS
Correct Answer: C
Rationale: The correct answer is C: Thick peptidoglycan layer. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet stain during Gram staining. This thick layer is a key characteristic feature that helps differentiate Gram-positive bacteria from Gram-negative bacteria.
Rationale:
1. Gram-positive bacteria retain the crystal violet stain due to their thick peptidoglycan layer.
2. This thick layer provides structural support and protection to the cell.
3. Gram-positive bacteria lack an outer membrane, which is a feature of Gram-negative bacteria (Choice A).
4. Thin peptidoglycan layer is a characteristic of Gram-negative bacteria, not Gram-positive (Choice B).
5. Presence of LPS (lipopolysaccharide) is a feature of Gram-negative bacteria, not Gram-positive (Choice D).
In summary, the presence of a thick peptidoglycan layer is a characteristic feature of Gram-positive