Nokea
Which photosynthetic pigments are found in all prokaryotic and eukaryotic photoautotrophs?
- A. chlorophyll c
- B. carotenoids
- C. phycobilins
- D. phycocyanin
Correct Answer: B
Rationale: The correct answer is B: carotenoids. Carotenoids are photosynthetic pigments that are found in all prokaryotic and eukaryotic photoautotrophs. They play a key role in capturing light energy for photosynthesis. Chlorophyll c, phycobilins, and phycocyanin are not found in all prokaryotic and eukaryotic photoautotrophs. Chlorophyll c is primarily found in certain algae, phycobilins are specific to cyanobacteria and red algae, and phycocyanin is a type of phycobilin found in cyanobacteria. Carotenoids are the only pigment that is universally present across all photoautotrophs.
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During the healing phase of inflammation, which cells would be mostly likely to regenerate?
- A. Skin
- B. Neurons
- C. Cardiac muscle
- D. Skeletal muscle
Correct Answer: A
Rationale: Skin cells are highly regenerative due to their rapid turnover rate and presence of stem cells. In contrast, neurons, cardiac muscle, and skeletal muscle have limited regenerative capacity.
All of the following can be a consequence of the formation of NETS with the exception of:
- A. Killing of microbes contained in phagolysosomes
- B. Death of neutrophils
- C. Trapping of microbes at sites of infection
- D. Extracellular microbial killing
Correct Answer: A
Rationale: The correct answer is A because NETs (Neutrophil Extracellular Traps) are released by neutrophils to trap and kill microbes extracellularly. Step 1: NETs are composed of DNA, histones, and antimicrobial proteins. Step 2: They trap microbes at the site of infection. Step 3: The antimicrobial proteins in NETs kill the trapped microbes. Step 4: Neutrophils themselves do not contain microbes inside phagolysosomes, so the killing of microbes contained in phagolysosomes is not a direct consequence of NET formation. Therefore, choice A is the exception. Choices B, C, and D are incorrect as they are all consequences of NET formation.
Which of the following is not a consequence of anaphylactic shock?
- A. Constriction of airways
- B. Loss of blood pressure
- C. Hives
- D. Binding of allergen-specific IgE to mast cells
Correct Answer: D
Rationale: The correct answer is D because the binding of allergen-specific IgE to mast cells is actually a key event in anaphylactic shock, leading to the release of inflammatory mediators. Constriction of airways (A), loss of blood pressure (B), and hives (C) are all consequences of anaphylactic shock due to the systemic release of histamine and other mediators. IgE binding to mast cells triggers the release of these mediators, causing the symptoms associated with anaphylaxis. Therefore, D is the correct answer as it is not a consequence but rather an initiating event in anaphylactic shock.
A 78-year-old patient has developed Haemophilus influenzae. In addition to standard precautions, what should the nurse use to protect herself and other patients when working within 3 feet of the patient?
- A. Mask
- B. Gown
- C. Gloves
- D. Shoe covers
Correct Answer: A
Rationale: Haemophilus influenzae is primarily transmitted via respiratory droplets. Wearing a mask is essential to prevent inhalation of these droplets within close proximity.
The C3 convertase is
- A. An opsonin facilitating the phagocytic process
- B. Part of the Membrane Attack Complex (MAC) that leads to lysis of targets
- C. An enzyme able to cleave C3
- D. An inhibitor of C3b
Correct Answer: C
Rationale: The correct answer is C because the C3 convertase is an enzyme that cleaves C3 into C3a and C3b, an essential step in the complement cascade. This enzyme is crucial for the initiation of both the classical and alternative pathways. Choice A is incorrect as opsonins enhance phagocytosis but are not directly related to C3 convertase. Choice B is incorrect as the MAC is formed by the terminal complement components, not the C3 convertase. Choice D is incorrect as C3b is not an inhibitor but a product of C3 cleavage by the C3 convertase.