1
1 Emulsification of fats occurs in the alimentary canal.
State the name of the structure in the villi where digested fats are absorbed.
.................................................................................................................................................. [1]
[Total: 1]
2
2 The diagram shows a drawing of a cell from the lining of the small intestine. The lumen is the space
inside the intestine where food is digested.
State the names of the three labelled structures in the diagram and describe the role of each
structure in the intestinal cell.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
.................................................................................................................................................. [6]
3
[Total: 6]
3 The epithelial cells of the small intestine have many microvilli.
State the role of the microvilli.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
.................................................................................................................................................. [2]
[Total: 2]
4
4 Carbohydrates are an important component of a balanced diet.
The flow chart shows some of the processes that happen to carbohydrates in food that is eaten.
Describe what happens to carbohydrates in the human body between ingestion and assimilation
in the liver.
5
Use the information in the flow chart as a guide.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
.................................................................................................................................................. [8]
[Total: 8]
5 State the name of one type of digested food molecule that is absorbed.
.................................................................................................................................................. [1]
[Total: 1]
6
6 Water is a very important molecule for all living organisms.
State the name of the organ in humans where most water is absorbed.
.................................................................................................................................................. [1]
[Total: 1]
7 In a medical investigation the number of villi in four people was compared. The results given in the
2
table below show the average number of villi present in 1 cm of ileum wall.
2
person average number of villi per cm
P 4200
Q 4500
R 3500
S 3200
Calculate the difference in the number of villi between person P and person S.
2
difference = ....................................................... per cm [1]
[Total: 1]
7
8 In a medical investigation the number of villi in four people was compared. The results given in the
2
table below show the average number of villi present in 1 cm of ileum wall.
2
person average number of villi per cm
P 4200
Q 4500
R 3500
S 3200
Further investigations showed that person Q could absorb digested food more rapidly than the
other people.
Use the information in the table to explain this result.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
.................................................................................................................................................. [3]
[Total: 3]
8
9 The diagram below shows a structure found in the wall of the small intestine.
State one function of this structure.
..................................................................................................................................................
.................................................................................................................................................. [1]
[Total: 1]
9
10 The diagram below shows a structure found in the wall of the small intestine.
Name the structure shown in the diagram
.................................................................................................................................................. [1]
[Total: 1]
11 The material entering the colon is liquid, but the faeces are usually much more solid.
State how this happens.
..................................................................................................................................................
.................................................................................................................................................. [1]
[Total: 1]
12 Name the part of the alimentary canal where most of the digested food is absorbed.
.................................................................................................................................................. [1]
[Total: 1]
10
13 Digestion food is absorbed as it passes along the small intestine.
Explain how this absorption takes place.
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
.................................................................................................................................................. [3]
[Total: 3]
14 The diagrams below show sections of a villus.
The diagram on the left shows a longitudinal section of a villus.
The diagram on the right shows a cross-section of the same villus at V - W.
The diagrams are not drawn to the same scale.
V W
microvilli
S
cell T
11
(a) (i) Name structures P, Q and R.
P .............................................................................................................................
Q.............................................................................................................................
R ............................................................................................................................. [3]
(ii) Cell T is an example of the cells that form the surface of the villi.
Explain why there are many microvilli on cell T.
................................................................................................................................
................................................................................................................................
................................................................................................................................
................................................................................................................................
................................................................................................................................ [2]
(iii) Some of the cells on the surface of the villi secrete mucus for protection.
Suggest what the villi need to be protected against.
................................................................................................................................
................................................................................................................................
................................................................................................................................
................................................................................................................................ [2]
[Total: 7]
