OBJECTIVE LIFE SCIENCE
SIGNALLING IMMUNOLOGY CANCER
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Capsules prevent Complement activation
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Surface lipid-carbohydrates of some Gram-negatives prevent MAC formation.
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Enzymatic digestion of C5a by Gram-positives.
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all of the above
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Detailed explanation-1: -Bacterial pathogens have evolved diverse strategies to avoid complement activation by mimicking host surfaces, attracting host complement regulators through surface-exposed proteins, or targeting complement components with secreted proteins.
Detailed explanation-2: -There are three pathways of complement activation: the classical pathway, which is triggered directly by pathogen or indirectly by antibody binding to the pathogen surface; the MB-lectin pathway; and the alternative pathway, which also provides an amplification loop for the other two pathways.
Detailed explanation-3: -Reaction Cascade of the Complement System: Classical, Alternative and Lectin Pathway, Amplification Loop, Terminal Pathway, and Membrane Attack Complex.