Multiple Choice
Which of the following clinical findings would a nurse most likely assess in a child with pneumococcal meningitis?
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1. Introduction to Microbiology
Introduction to Microbiology
Multiple Choice
Which of the following statements best explains the difference in LD50 values between exotoxins and endotoxins?
A
Exotoxins have a much lower LD50 than endotoxins, meaning they are more potent.
B
Exotoxins and endotoxins have similar LD50 values, indicating equal toxicity.
C
Endotoxins have a much lower LD50 than exotoxins, meaning they are more potent.
D
LD50 values are not used to compare the potency of exotoxins and endotoxins.
Verified step by step guidance1
Step 1: Understand what LD50 means. LD50, or lethal dose 50, is the amount of a toxin required to kill 50% of a test population. A lower LD50 indicates higher potency because less toxin is needed to cause death.
Step 2: Review the characteristics of exotoxins. Exotoxins are proteins secreted by bacteria, often highly specific and potent, and can cause damage at very low concentrations.
Step 3: Review the characteristics of endotoxins. Endotoxins are lipopolysaccharide components of the outer membrane of Gram-negative bacteria, generally less potent and released mainly when bacteria die and lyse.
Step 4: Compare the LD50 values of exotoxins and endotoxins. Since exotoxins are more potent, their LD50 values are much lower than those of endotoxins, meaning smaller amounts cause lethal effects.
Step 5: Conclude that the statement 'Exotoxins have a much lower LD50 than endotoxins, meaning they are more potent' best explains the difference in LD50 values between these two toxin types.
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