Question
The diagram shows a large food molecule changing into smaller molecules.
What is process X?
A absorption
B chewing
C digestion
D secretion
Answer/Explanation
Ans
C
Question
The diagram shows part of the alimentary canal and associated organs.
Which structures secrete enzymes that digest proteins?
A T and U B U and V C V and W D W and T
Answer/Explanation
Ans
C
Question
The graph shows pH changes in the mouth after eating.
Why is it a good idea to brush teeth after eating?
A Acidic conditions help bacteria to grow.
B Acids dissolve tooth enamel.
C Alkaline conditions help bacteria to grow.
D Alkalis dissolve tooth enamel.
Answer/Explanation
Ans
B
Question
The cholera bacterium produces toxins that cause chloride ions to be secreted into the small
intestine.
How does this affect the water potential of blood in the intestinal capillaries and the intestinal
contents?
Answer/Explanation
Ans: C
Question
Cholera infection can cause the following events:
1 cells lining the small intestine secrete chloride ions
2 cholera bacteria produce a toxin
3 chloride ions move into the small intestine
4 water from the blood moves into the small intestine by osmosis
5 water potential of fluid in the small intestine becomes lower.
Which sequence of events will cause diarrhoea?
A 1 → 3 → 2 → 4 → 5
B 2 → 1 → 3 → 5 → 4
C 3 → 1 → 4 → 5 → 2
D 2 → 3 → 1 → 4 → 5
Answer/Explanation
Ans: B