BIOLOGY 5090 · STRUCTURED PRACTICE
Cholera is an acute transmissible water-borne disease caused by the bacterium Vibrio cholerae.
Define the term pathogen and state two distinct indirect routes by which pathogens can be transmitted from host to host.
Explain how the following structures act as barriers to pathogen invasion:
goblet cells and ciliated epithelial cells in the human gas exchange system
hydrochloric acid in gastric juice
Describe the physiological sequence of events by which the cholera enterotoxin causes severe watery diarrhoea in the small intestine.
Explain why administering an Oral Rehydration Solution (containing water, glucose, and sodium chloride) is effective in saving the life of a cholera patient, whereas drinking unboiled river water is ineffective and dangerous.
Total: 11 marks