Nokea
Based on studies of 16S ribosomal RNA and cell wall composition, which of the following bacteria are classified as Archaea?
- A. Halobacterium
- B. Methanococcus
- C. Sulfolobus
- D. Desulfovibrio
Correct Answer: D
Rationale: The correct answer is D: Desulfovibrio. Archaea are distinguished by their unique 16S ribosomal RNA sequences and cell wall composition. Desulfovibrio belongs to the Archaea domain due to its 16S rRNA sequence similarity and lack of peptidoglycan in the cell wall. Halobacterium, Methanococcus, and Sulfolobus are all classified as Archaea based on these criteria, making them incorrect choices.
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While caring for an 84-year-old patient, the nurse monitors the patient’s fluid and electrolyte balance, recognizing what as a normal change of aging?
- A. Hyperkalemia
- B. Hyponatremia
- C. Decreased insensible fluid loss
- D. Increased plasma oncotic pressures
Correct Answer: B
Rationale: Elderly individuals often experience hyponatremia due to reduced thirst sensation, impaired renal function, and decreased ability to concentrate urine.
Which of the following is NOT an organ-specific autoimmune disease
- A. Multiple sclerosis
- B. Lupus
- C. Diabetes
- D. Hashimoto's thyroiditis
Correct Answer: B
Rationale: The correct answer is B: Lupus. Lupus is a systemic autoimmune disease that can affect multiple organs and tissues throughout the body, rather than being specific to a single organ. Multiple sclerosis (A) is a neurological autoimmune disease affecting the central nervous system. Diabetes (C) is an autoimmune disease that affects the pancreas. Hashimoto's thyroiditis (D) is an autoimmune disease targeting the thyroid gland. Lupus does not specifically target a single organ, making it the correct choice.
Which is not a PAMP?
- A. Viral dsRNA
- B. Peptidoglycan
- C. ROS
- D. Flagellin
Correct Answer: C
Rationale: The correct answer is C: ROS (Reactive Oxygen Species) is not a PAMP (Pathogen-Associated Molecular Pattern) because it is not a specific molecular pattern derived from pathogens. PAMPs are recognized by the innate immune system to trigger an immune response. Viral dsRNA, peptidoglycan, and flagellin are all examples of PAMPs as they are specific molecules commonly found in pathogens that can be recognized by pattern recognition receptors (PRRs) on immune cells, leading to activation of the immune response.ROS, on the other hand, are reactive molecules produced by host cells in response to pathogens but are not specific molecular patterns derived from pathogens. Therefore, ROS is not considered a PAMP.
The human retina contains rods and cone which are able to
- A. convert the photo power to the chemical power
- B. absorption of ultraviolet
- C. convert photo power to electrical form and send action potentials to the brain
- D. absorption of infrared
Correct Answer: C
Rationale: The correct answer is C because rods and cones in the human retina convert light energy into electrical signals through phototransduction, which are then sent as action potentials to the brain via the optic nerve. This process allows for visual information to be transmitted and processed by the brain. Choice A is incorrect as it refers to the conversion of light energy to chemical energy, which is not the primary function of rods and cones. Choice B is incorrect as rods and cones do not specifically absorb ultraviolet light. Choice D is incorrect as rods and cones do not absorb infrared light.
Which of the following is a physical barrier provided by innate immunity?
- A. Antibodies
- B. T lymphocytes
- C. Tight junctions in epithelial cells
- D. Phagocytosis
Correct Answer: C
Rationale: The correct answer is C: Tight junctions in epithelial cells. These junctions physically prevent pathogens from entering the body. Antibodies (A) and T lymphocytes (B) are components of adaptive immunity, not physical barriers. Phagocytosis (D) is a cellular process, not a physical barrier.