Question

the source of the first epidemiological study was caused by a bacteria in london. what was the disease that was traced to poor sanitation? typhoid fever diphtheria impetigo cholera question 31 (1 point) the classical pathway for compliment activation is initiated by factors released by damaged tissues antigen - antibody reactions lipid - carohydrate complexes and c3 factors released fro phagocytosis

Explanation:

First Question (Epidemiological Study in London)

The first epidemiological study in London (by John Snow) traced cholera to contaminated water (poor sanitation). Cholera is caused by Vibrio cholerae and spreads via water/food with poor sanitation. Typhoid, diphtheria, and impetigo do not match this historical context.

The classical complement pathway is initiated by antigen - antibody (immune complex) reactions. The alternative pathway is triggered by factors from damaged tissues or pathogen - associated molecules, and the lectin pathway by carbohydrate - binding. Lipid - carbohydrate complexes and C3 are not classical triggers, nor are factors from phagocytosis.

Answer:

D. Cholera

Question 31 (Complement Activation Pathway)