Digestion — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

3 An enzyme from the alimentary canal has an optimum activity at an acidic pH. Which statement is correct? A The enzyme is an amylase and is found in the mouth. B The enzyme is a protease and is found in the mouth. C The enzyme is an amylase and is found in the stomach. D The enzyme is a protease and is found in the stomach.

1 marks

Answer: D

This question in 0654/23 May/June 2017

9 The diagram shows a section through a villus. X What is the function of structure X? A to absorb amino acids from the intestine B to absorb fatty acids from the intestine C to transport enzymes to the intestine D to transport water to the intestine

1 marks

Answer: B

This question in 0654/21 Oct/Nov 2017

8 What is a function of bile? A emulsifying carbohydrates to decrease the surface area for the action of enzymes B emulsifying carbohydrates to increase the surface area for the action of enzymes C emulsifying fats to decrease the surface area for the action of enzymes D emulsifying fats to increase the surface area for the action of enzymes

1 marks

Answer: D

This question in 0654/22 Oct/Nov 2017

1 What are the optimum conditions of pH and temperature for the action of protease in the stomach? temperature pH / °C A 2 27 B 2 37 C 7 27 D 7 37

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2018

6 The diagram shows the structure of a villus. Which structure absorbs and carries away amino acids? B C D A

1 marks

Answer: C

This question in 0654/23 Oct/Nov 2018

6 What is the correct definition of ingestion? A The breakdown of large, insoluble food molecules into small, water-soluble molecules. B The movement of digested food molecules through the wall of the small intestine into the blood. C The passing out of food that has not been digested, as faeces, through the anus. D The taking of substances into the body through the mouth.

1 marks

Answer: D

This question in 0654/22 May/June 2019

6 What is the effect of bile on food after it leaves the stomach? A acidifies the food entering the duodenum B activates enzymes which digest glycerol C increases the surface area of fats for digestion D provides fat for digesting enzymes

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2019

6 Where is bile stored? A gall bladder B liver C pancreas D stomach

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2019

6 The diagram shows part of the alimentary canal and associated organs. Where is lipase produced? C D B A

1 marks

Answer: A

This question in 0654/22 Feb/March 2021

6 Protein shakes can be used by athletes to supplement their diet. They are a drink made by dissolving protein powders in water or milk. Which types of digestion will be required before they can be absorbed? chemical mechanical digestion digestion Jv v key /=yes 0 Oo WwW > Jv x x v X=no x x

1 marks

Answer: B

This question in 0654/21 May/June 2021

6 Which row about secretions in the alimentary canal is correct? substance area of action secreted alimentary canal A amylase breaks down fats into fatty acids and glycerol small intestine B bile breaks down fats into fatty acids and glycerol small intestine C hydrochloric acid breaks down proteins to amino acids stomach D protease breaks down proteins to amino acids stomach

1 marks

Answer: D

This question in 0654/22 May/June 2021

6 A mixture of starch suspension and saliva is placed inside a bag with a partially permeable membrane. The bag is placed into a test-tube filled with distilled water, as shown. After one hour, the water is found to contain glucose. distilled water starch suspension mixed with saliva partially permeable membrane Which row explains this result? movement of glucose type of digestion through partially permeable membrane A chemical diffusion B chemical osmosis C mechanical diffusion D mechanical osmosis

1 marks

Answer: A

This question in 0654/23 May/June 2021

4 An investigation was carried out to see the effect of pH on the activity of an enzyme found in the human alimentary canal. The graph shows the results obtained. activity of enzyme 1 2 3 pH What is the enzyme? A a protease found in the mouth B a protease found in the stomach C an amylase found in the mouth D an amylase found in the stomach

1 marks

Answer: B

This question in 0654/21 Oct/Nov 2021

6 What is the name of the process which moves soluble food molecules through the wall of the small intestine into the blood? A absorption B assimilation C digestion D ingestion

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2021

6 The diagram shows the optimum pH for two different enzymes X and Y. X Y enzyme activity 1 2 3 4 5 6 7 8 9 pH Which enzyme, X or Y, could be amylase and from which organ could this amylase be secreted? site of enzyme secretion A X pancreas B X stomach C Y pancreas D Y stomach

1 marks

Answer: C

This question in 0654/23 Oct/Nov 2021

6 What is assimilation? A the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells B the movement of digested food molecules through the wall of the intestine into the blood C the passing out of food that has not been digested, as faeces, through the anus D the taking of food and drink into the body through the mouth

1 marks

Answer: A

This question in 0654/22 Feb/March 2022

6 The diagram shows part of the digestive system. P Q R S Which labelled parts produce digestive enzymes, absorb water and store bile? produce digestive absorb water store bile enzymes A P Q R B Q R P C R S P D S P R

1 marks

Answer: C

This question in 0654/21 May/June 2022

6 The diagram shows part of the digestive system. P Q R S Which labelled parts produce digestive enzymes, absorb water and store bile? produce digestive absorb water store bile enzymes A P Q R B Q R P C R S P D S P R

1 marks

Answer: C

This question in 0654/22 May/June 2022

6 The diagram shows part of the digestive system. P Q R S Which labelled parts produce digestive enzymes, absorb water and store bile? produce digestive absorb water store bile enzymes A P Q R B Q R P C R S P D S P R

1 marks

Answer: C

This question in 0654/23 May/June 2022

6 Which features of villi help to maximise the absorption of digested food? 1 a good blood supply 2 a large surface area 3 the presence of enzymes 4 the presence of lacteals A 1, 2 and 4 B 1, 3 and 4 C 1 and 3 only D 2 and 4 only

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2022

6 The diagram shows the human alimentary canal. P S R Q In which labelled organs are large insoluble molecules broken down into small soluble molecules? A P and R B R and S C S and Q D Q and P

1 marks

Answer: A

This question in 0654/22 Feb/March 2023

6 Some processes that occur in the alimentary canal and associated organs are listed. 1 absorption 2 assimilation 3 digestion 4 egestion 5 ingestion Which diagram correctly links each process to the part of the alimentary canal or associated organs? A B 5 3 1 3 1 5 2 4 4 2 C D 4 5 2 3 2 3 1 1 5 4

1 marks

Answer: D

This question in 0654/21 May/June 2023

6 What is one of the functions of bile? A denaturing lipase B digesting fats C emulsifying fats D increasing acidity

1 marks

Answer: C

This question in 0654/22 May/June 2023

6 Pancreatic insufficiency is a condition that occurs when the pancreas is unable to produce enough enzymes. Which secretions are reduced due to this condition? A amylase, lipase and protease B amylase, lipase and bile C amylase, insulin and protease D glucagon, insulin and protease

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2023

6 Which statements about mechanical digestion are correct? 1 Food is broken down into smaller pieces. 2 Food molecules do not undergo chemical changes. 3 Soluble molecules are formed from insoluble ones. 4 Large molecules are broken down to smaller ones. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2023

6 Humans have different types of teeth. Which type of tooth is used for biting off food? A canines B incisors C premolars D molars

1 marks

Answer: B

This question in 0654/21 May/June 2024

6 A student investigates the effect of size of gelatine cubes on the rate of digestion by protease. The student places a cube of gelatine with a volume of 8 cm3 into a beaker of protease. The time taken for the cube to be digested is recorded. A second 8 cm3 cube of gelatine is cut up into eight 1 cm3 cubes to represent mechanical digestion and the experiment is repeated. The results are shown. time taken to digest gelatine the gelatine / minutes one 8 cm3 cube 320 eight 1 cm3 cubes 80 Which statements are correct? 1 Cutting up the 8 cm3 cube increases the surface area exposed to the enzyme. 2 Chemical digestion cannot occur unless mechanical digestion also occurs. 3 Mechanical digestion increases the rate of chemical digestion. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: C

This question in 0654/22 May/June 2024

6 Which row about secretions in the alimentary canal is correct? substance area of action secreted alimentary canal A amylase breaks down fats into fatty acids and glycerol small intestine B bile breaks down fats into fatty acids and glycerol small intestine C hydrochloric acid breaks down proteins into amino acids stomach D protease breaks down proteins into amino acids stomach

1 marks

Answer: D

This question in 0654/23 May/June 2024

6 The diagram shows a villus. P Q What are structures P and Q and which substances do they absorb? structure substance absorbed amino fatty capillary lacteal acids acids A P Q P Q B P Q Q P C Q P P Q D Q P Q P

1 marks

Answer: D

This question in 0654/21 Oct/Nov 2024

6 Protein shakes are used by athletes to supplement their diet. They are a drink made by dissolving protein powders in water or milk. Which types of digestion will be required before they can be absorbed? chemical mechanical digestion digestion WA J 0 0O WwW D> v x x v x x

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2024

7 Starch is chemically digested into maltose by the enzyme amylase. What are the properties of the maltose molecules? A large and insoluble B large and soluble C small and insoluble D small and soluble

1 marks

Answer: D

This question in 0654/22 May/June 2025

4 Which row shows the parts of the alimentary canal where the enzymes amylase, lipase and protease are secreted? mouth small intestine stomach A amylase protease amylase B amylase lipase protease C protease protease lipase D protease lipase lipase

1 marks

Answer: B

This question in 0654/23 May/June 2025

7 Which row about digestion is correct? type of digestion before digestion after digestion A chemical large pieces of food small pieces of food B chemical large insoluble molecules small soluble molecules C physical large soluble molecules small insoluble molecules D physical large pieces of food small soluble molecules

1 marks

Answer: B

This question in 0654/21 Oct/Nov 2025

6 The diagram shows part of the human digestive system. P Q R S Which organs produce digestive enzymes? A P and Q B Q and R C R and S D S and P

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2025