Nokea
Which of the following represents the correct sequence of host immune defenses as encountered by a pathogen?
- A. Innate responses; physical barriers; adaptive responses
- B. Physical barriers; innate responses; adaptive responses
- C. Adaptive responses; physical barriers; innate responses
- D. Physical barriers; adaptive responses; innate responses
Correct Answer: B
Rationale: The correct sequence is B: Physical barriers; innate responses; adaptive responses. Physical barriers like skin and mucous membranes are the first line of defense, followed by innate responses (e.g., inflammation, phagocytosis) that provide immediate, non-specific protection. Adaptive responses (e.g., antibody production, T cell activation) are the final defense mechanism, specifically targeting the pathogen. Choices A, C, and D are incorrect because they do not follow the correct chronological order of how host immune defenses are encountered by a pathogen. Option A and D have the innate and adaptive responses in the wrong order, while option C places adaptive responses before physical barriers, which is not accurate in terms of the sequence of host immune defenses.
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Which of the following characteristics do not occur in prokaryotic cells?
- A. cellular organization
- B. thylakoid membranes within chloroplasts
- C. oxygenic photosynthesis
- D. anaerobic respiration
Correct Answer: B
Rationale: The correct answer is B: thylakoid membranes within chloroplasts. Prokaryotic cells lack membrane-bound organelles like chloroplasts, where thylakoid membranes are found. This is a key feature of prokaryotic cells. Choices A, C, and D are characteristics that can occur in prokaryotic cells. Cellular organization is present in prokaryotic cells, oxygenic photosynthesis can be carried out by some prokaryotic organisms, and prokaryotic cells can perform anaerobic respiration.
What type of cell is responsible for carrying oxygen and carbon dioxide in the body?
- A. Red blood cell
- B. White blood cell
- C. Platelet
- D. Hematocrit
Correct Answer: A
Rationale: The correct answer is A: Red blood cell. Red blood cells, also known as erythrocytes, contain hemoglobin that binds to oxygen and carbon dioxide for transport in the bloodstream. They are specifically designed for gas exchange. White blood cells (B) are part of the immune system and fight infections. Platelets (C) are responsible for blood clotting. Hematocrit (D) refers to the proportion of red blood cells in the blood, not a specific type of cell responsible for gas transport.
The nurse is assessing a client for signs and symptoms of systemic lupus erythematosus (SLE). Which of the following would be consistent with this disorder? (Select one that does not apply.)
- A. Discoid rash on skin exposed to sunlight
- B. Urinalysis negative for casts and protein
- C. Painful, deformed small joints
- D. Pain on inspiration
Correct Answer: A
Rationale: The correct answer is A: Discoid rash on skin exposed to sunlight. Systemic lupus erythematosus (SLE) commonly presents with a characteristic butterfly-shaped rash on the face, especially over the cheeks and nose, that worsens with sunlight exposure. The rash is not limited to skin exposed to sunlight. Choices B, C, and D are inconsistent with SLE. B: Urinalysis negative for casts and protein is not indicative of SLE, as renal involvement in SLE often presents with the presence of casts and protein in the urine. C: Painful, deformed small joints is more typical of rheumatoid arthritis, not SLE. D: Pain on inspiration is a symptom of pleurisy, which can occur in SLE but is not a defining feature.
Which immunoglobulin is the principal one found in secretions such as milk?
- A. IgG
- B. IgM
- C. IgA
- D. IgD
Correct Answer: C
Rationale: The correct answer is C: IgA. IgA is the principal immunoglobulin found in secretions like milk due to its role in mucosal immunity. IgG is mainly found in the blood and provides systemic immunity. IgM is the first antibody produced during an immune response. IgD is primarily found on the surface of B cells and is involved in B cell activation. IgA is the most abundant immunoglobulin in mucosal secretions, making it the principal one found in milk.
In reference to the flow diagram below respond to the following question. The annotation A refers to which sites
- A. Annealing
- B. Melting
- C. Restriction
- D. RNAse
Correct Answer: C
Rationale: The correct answer is C: Restriction. In a flow diagram, the annotation "Restriction" likely indicates the site where a DNA molecule is being cut by a restriction enzyme. This process is essential in molecular biology for DNA manipulation.
Choice A: Annealing involves the process of complementary DNA strands coming together, usually during PCR or hybridization.
Choice B: Melting refers to the separation of double-stranded DNA into single strands, often seen in denaturation steps.
Choice D: RNAse is an enzyme that specifically degrades RNA molecules, not involved in the DNA manipulation processes indicated in the diagram.