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Question 18M.3.SL.TZ2.16

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Date May 2018 Marks available [Maximum mark: 6] Reference code 18M.3.SL.TZ2.16
Level SL Paper 3 Time zone TZ2
Command term Explain, Outline Question number 16 Adapted from N/A
16.
[Maximum mark: 6]
18M.3.SL.TZ2.16
(a)

Explain the relationship between infection by the bacterium Vibrio cholerae and dehydration.

[3]

Markscheme

a. V. cholerae releases toxin 

b. chloride channels activated 

c. chloride ions are pumped out of cells 

d. leading to fluid loss from intestine/diarrhea 

e. associated vomiting contributes to dehydration

Examiners report

 

(b)

Severe dehydration can lead to cardiac arrest. Outline the use of defibrillation to treat life-threatening cardiac conditions.

[3]

Markscheme

a. defibrillator is electrodes / a metal paddle or / a pad that is placed on the patient’s chest 

b. the device determines whether fibrillation is happening 

c. a series of electrical shocks are delivered «through the electrodes» 

d. electrical impulse is used to depolarize the heart muscle 

e. to re-establish the function of the SA node / natural pacemaker / natural rhythm «of the heart»

Examiners report