Nokea
Some of the viruses have a cubic type of symmetry, which in the shape of:
- A. Icosahedral structures
- B. Hexahedral structure
- C. Tetrahedral structure
- D. Dodecahedral structure
Correct Answer: A
Rationale: The correct answer is A: Icosahedral structures. Icosahedral symmetry is commonly found in viruses due to its efficient way of packing genetic material. The icosahedron has 20 equilateral triangular faces, making it ideal for viral capsids. The other choices, B: Hexahedral, C: Tetrahedral, and D: Dodecahedral structures, do not accurately describe the cubic type of symmetry seen in viruses. Hexahedral refers to a six-faced polyhedron, tetrahedral to a four-faced polyhedron, and dodecahedral to a twelve-faced polyhedron, none of which align with the structure commonly observed in viruses.
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A 25-year-old woman is complaining of burning and painful urination. The microbiological analysis detects significant bacterial growth only on blood agar and it is without hemolysis. Gram-positive cocci are observed on microscopic slides. Which bacterium is the most probable cause?
- A. Proteus mirabilis
- B. Staphylococcus saprophytic
- C. Staphylococcus aureus
- D. Pseudomonas aeruginosa
Correct Answer: B
Rationale: The correct answer is Staphylococcus saprophyticus (choice B). This bacterium is a common cause of urinary tract infections in young women. It typically grows on blood agar without hemolysis and appears as Gram-positive cocci under the microscope. Proteus mirabilis (choice A) is known for urease production, causing alkaline urine. Staphylococcus aureus (choice C) is a common cause of skin and soft tissue infections, not urinary tract infections. Pseudomonas aeruginosa (choice D) is an opportunistic pathogen often seen in nosocomial infections, not typically associated with urinary tract infections in healthy individuals.
CDC stands for:
- A. Centers for Disease Control and Prevention
- B. Children’s Disease Center
- C. Central Disaster Control Center
- D. Central Drug Evaluation and Control Center
Correct Answer: A
Rationale: The correct answer is A: Centers for Disease Control and Prevention. The CDC is a U.S. government agency responsible for protecting public health and safety. The correct answer is the only choice that accurately reflects the agency's purpose. Choice B (Children's Disease Center) is incorrect because the CDC's scope is not limited to children's health. Choice C (Central Disaster Control Center) is incorrect as the CDC primarily focuses on disease prevention. Choice D (Central Drug Evaluation and Control Center) is incorrect as the CDC's main focus is not on drug evaluation. Thus, the correct answer is A as it aligns with the CDC's mission and responsibilities.
What do bacterial ribosomes do?
- A. Synthesize proteins
- B. Synthesize DNA
- C. Degrade toxic substances
- D. Assist in cell division
Correct Answer: A
Rationale: The correct answer is A: Bacterial ribosomes synthesize proteins. Ribosomes are cellular organelles responsible for protein synthesis by translating mRNA into amino acids. They are essential for the production of proteins needed for cell function. Choices B, C, and D are incorrect because ribosomes do not synthesize DNA, degrade toxic substances, or assist in cell division. DNA synthesis is carried out by DNA polymerase, degradation of toxic substances is typically done by enzymes, and cell division is primarily regulated by the cell cycle machinery.
Saddle nose is characteristic of which of the following congenital infections?
- A. Syphilis
- B. CMV
- C. Rubella
- D. Toxoplasmosis
Correct Answer: A
Rationale: Saddle nose is a condition where the bridge of the nose collapses, a characteristic feature of congenital syphilis. This occurs due to inflammation and destruction of cartilage. Syphilis is caused by the bacterium Treponema pallidum. CMV, Rubella, and Toxoplasmosis do not typically cause saddle nose. CMV can result in hearing loss, Rubella can lead to cataracts and heart defects, and Toxoplasmosis may cause hydrocephalus or chorioretinitis.
The female reproductive system includes the following organs/structures:
- A. Ovaries, kidneys, uterus, vagina
- B. Uterus, vagina, bladder, duodenum
- C. Bladder, ureter, vagina, uterus
- D. Uterus, ovaries, vagina, fallopian tubes
Correct Answer: D
Rationale: The correct answer is D because the female reproductive system consists of the uterus, ovaries, vagina, and fallopian tubes. The ovaries produce eggs, the fallopian tubes transport the eggs to the uterus, where fertilization can occur. The vagina is the birth canal and where sperm is deposited during intercourse. The uterus is where a fertilized egg implants and a fetus develops.
Choice A is incorrect because it includes the kidneys, which are part of the urinary system, not the reproductive system.
Choice B is incorrect because it includes the bladder and duodenum, which are part of the urinary and digestive systems, respectively, not the reproductive system.
Choice C is incorrect because it includes the bladder and ureter, which are part of the urinary system, not the reproductive system.