IGCSE Biology Topic 7: Human Nutrition MCQs – 30 Practice Questions with Answers (Cambridge 0610)
Free practice for Cambridge IGCSE Biology 0610 on human nutrition, covering diet, the digestive system, enzymes and absorption, with every question followed by a short worked explanation.
Diet and Deficiency Diseases
Q1. A balanced diet is best described as a diet that provides what?
- (A) The same amount of every nutrient each day, regardless of age or activity
- (B) All the nutrients needed, in the right proportions for that person
- (C) As much protein as possible, with very little carbohydrate or fat
- (D) Only foods grown locally, eaten in large quantities
Show Answer
Answer: B – A balanced diet matches the amounts of each nutrient to the needs of the individual, so the same diet is not right for everyone.
Q2. Which food group is the main source of energy for most everyday activities?
- (A) Mineral ions, such as calcium and iron
- (B) Fibre
- (C) Carbohydrates
- (D) Vitamins
Show Answer
Answer: C – Carbohydrates are broken down to glucose, which is used in respiration to release energy.
Q3. A child who eats almost no dairy products and gets very little sunlight is most at risk of which condition?
- (A) Rickets, because vitamin D and calcium build healthy bones
- (B) Scurvy, because the diet lacks the vitamin needed for healthy gums
- (C) Anaemia, because the diet lacks the mineral needed to make haemoglobin
- (D) Kwashiorkor, because the diet lacks sufficient protein for growth
Show Answer
Answer: A – Vitamin D helps the body absorb calcium, and without either, bones grow soft and weak, which is rickets.
Q4. Why does a diet low in iron lead to tiredness and pale skin?
- (A) Iron is needed to make bile, so fats cannot be digested properly
- (B) Iron is needed to build cell membranes, so cells break down easily
- (C) Iron is needed to make digestive enzymes, so food passes through undigested
- (D) Iron is needed to make haemoglobin
Show Answer
Answer: D – Haemoglobin in red blood cells contains iron, and without enough of it the blood carries less oxygen to respiring tissues.
Q5. Which pair correctly matches a nutrient with one of its roles in the body?
- (A) Fibre – builds new muscle tissue after exercise
- (B) Protein – provides amino acids for growth and repair
- (C) Water – supplies most of the energy used in respiration
- (D) Vitamin C – strengthens bones by helping calcium absorption
Show Answer
Answer: B – Proteins are broken down to amino acids, which cells reassemble into new proteins for growth and repair.
Q6. Scurvy develops when the diet lacks vitamin C for a long period. Which symptom is most characteristic of scurvy?
- (A) Bleeding gums and slow healing of wounds
- (B) Soft, bent bones in growing children
- (C) Swollen ankles caused by fluid collecting in tissues
- (D) Night blindness in dim light
Show Answer
Answer: A – Vitamin C is needed to maintain connective tissue, so a shortage leads to bleeding gums and wounds that heal poorly.
Q7. What is the main function of fibre (roughage) in the diet?
- (A) To provide amino acids for building enzymes
- (B) To dissolve fat-soluble vitamins so they can be absorbed
- (C) To keep food moving through the gut
- (D) To neutralise stomach acid in the small intestine
Show Answer
Answer: C – Fibre adds bulk to the contents of the gut, which stimulates the muscles of the gut wall to move food along.
Q8. Which statement about fats and oils in the diet is correct?
- (A) They are broken down in the mouth by amylase
- (B) They provide no energy and are only used for insulation
- (C) They are the main source of amino acids for growth
- (D) They provide energy and build cell membranes
Show Answer
Answer: D – Fats are energy-rich and their fatty acids and glycerol are used in making membranes and other cell materials.
The Digestive System and Physical Digestion
Q9. In which order does food pass through the parts of the alimentary canal?
- (A) Mouth, oesophagus, stomach, small intestine, large intestine
- (B) Mouth, stomach, oesophagus, large intestine, small intestine and rectum
- (C) Oesophagus, mouth, stomach, large intestine, small intestine
- (D) Mouth, oesophagus, small intestine, stomach, large intestine
Show Answer
Answer: A – Food is swallowed down the oesophagus to the stomach, then passes through the small intestine before reaching the large intestine.
Q10. Which organ stores bile until it is needed in the small intestine?
- (A) The pancreas
- (B) The gall bladder
- (C) The liver
- (D) The stomach
Show Answer
Answer: B – Bile is made in the liver but stored and concentrated in the gall bladder, then released into the duodenum.
Q11. A student describes four processes: taking food into the mouth, breaking food down, moving nutrients into the blood, and removing undigested food as faeces. Which term describes the removal of undigested food as faeces?
- (A) Ingestion
- (B) Digestion
- (C) Assimilation
- (D) Egestion
Show Answer
Answer: D – Egestion is the removal of undigested material, whereas ingestion is taking food in and assimilation is the use of nutrients by cells.
Q12. Which teeth are best adapted for cutting food into bite-sized pieces at the front of the mouth?
- (A) Molars, with broad, flat surfaces for grinding food thoroughly
- (B) Premolars, with two points for crushing
- (C) Incisors, with sharp, chisel-shaped edges
- (D) Canines, with pointed crowns for tearing
Show Answer
Answer: C – Incisors have a sharp edge that cuts food, while canines tear and molars and premolars crush and grind.
Q13. What is the function of enamel in a human tooth?
- (A) To form a hard outer covering for the tooth
- (B) To carry nerves that detect temperature changes in food
- (C) To anchor the tooth firmly into the jaw bone
- (D) To supply blood to the living pulp inside the tooth
Show Answer
Answer: A – Enamel is the hardest material in the body and covers the crown, protecting the softer dentine beneath it.
Q14. How does the stomach contribute to physical digestion?
- (A) It absorbs amino acids directly into the blood through its walls
- (B) It produces bile to emulsify fats before they reach the intestine
- (C) It secretes amylase to begin the digestion of starch
- (D) Its muscular walls churn food into smaller pieces
Show Answer
Answer: D – Churning by the stomach wall breaks food into smaller pieces and mixes it thoroughly, increasing the surface area for enzymes.
Q15. Why does physical digestion help chemical digestion to work faster?
- (A) It raises the temperature of food to the optimum for enzymes
- (B) It increases the surface area of food exposed to enzymes
- (C) It changes starch molecules into glucose without enzymes
- (D) It removes water from food so enzymes are more concentrated
Show Answer
Answer: B – Smaller pieces have a larger total surface area, so more enzyme molecules can act on the food at the same time.
Chemical Digestion and Absorption
Q16. Which enzyme breaks down starch, and what is its first product in the human gut?
- (A) Lipase, producing fatty acids and glycerol
- (B) Protease, producing amino acids
- (C) Amylase, producing maltose
- (D) Maltase, producing glucose
Show Answer
Answer: C – Amylase breaks starch down to maltose, and maltase on the lining of the small intestine then breaks maltose to glucose.
Q17. Pepsin and trypsin are both proteases, but they work in different places. What is the key difference between their working conditions?
- (A) Pepsin works in the acidic conditions of the stomach, while trypsin works in the alkaline conditions of the small intestine
- (B) Pepsin works in the alkaline conditions of the stomach, while trypsin works in the acidic conditions of the small intestine, at body temperature
- (C) Pepsin works only on fats, while trypsin works only on starch
- (D) Pepsin works in the mouth, while trypsin works in the large intestine
Show Answer
Answer: A – The stomach provides acidic conditions for pepsin, whereas the small intestine is alkaline, suiting trypsin.
Q18. What is the role of hydrochloric acid in gastric juice, apart from killing microorganisms in food?
- (A) It emulsifies fats so lipase can act on them
- (B) It breaks starch down to maltose
- (C) It absorbs glucose into the blood
- (D) It provides an acidic pH for stomach enzymes
Show Answer
Answer: D – Hydrochloric acid lowers the pH of the stomach contents to the optimum for pepsin, as well as killing many harmful microorganisms.
Q19. Bile is described as an alkaline mixture. How does this property help digestion in the duodenum?
- (A) It makes the duodenum acidic so pepsin can continue working
- (B) It neutralises acid arriving from the stomach
- (C) It dissolves starch directly into glucose
- (D) It kills all bacteria in the small intestine
Show Answer
Answer: B – Neutralising stomach acid protects the enzymes of the small intestine, which need alkaline conditions to work well.
Q20. How does bile help the chemical digestion of fats, even though bile contains no enzymes?
- (A) It breaks fats directly into fatty acids and glycerol
- (B) It dissolves fats completely in water
- (C) It emulsifies fats into tiny droplets for lipase
- (D) It carries fats into the blood through the villi
Show Answer
Answer: C – Emulsification splits large fat globules into droplets, so lipase has far more surface to act on.
Q21. Where is lipase secreted, and where does it act?
- (A) Secreted in the mouth, acts in the stomach
- (B) Secreted in the stomach, acts in the large intestine after food leaves the small intestine
- (C) Secreted in the liver, acts in the gall bladder
- (D) Secreted by the pancreas, acts in the small intestine
Show Answer
Answer: D – Pancreatic lipase is released into the duodenum, where it breaks fats and oils into fatty acids and glycerol.
Q22. Which statement correctly describes chemical digestion?
- (A) It breaks large insoluble molecules into small soluble molecules that can be absorbed
- (B) It breaks food into smaller pieces without changing the food molecules
- (C) It moves nutrients from the intestine into the blood
- (D) It stores excess glucose as glycogen in the liver
Show Answer
Answer: A – Chemical digestion changes large insoluble molecules into small soluble ones; breaking food into pieces without chemical change is physical digestion.
Q23. Which feature of a villus most directly speeds up the absorption of glucose into the blood?
- (A) A thick wall that stores glucose until it is needed
- (B) A rich capillary network that carries absorbed glucose away, maintaining a concentration gradient
- (C) A layer of mucus that dissolves glucose
- (D) Muscle fibres that churn the contents of the intestine
Show Answer
Answer: B – Blood flowing through the capillaries removes glucose as fast as it arrives, so diffusion into the blood continues rapidly.
Q24. What is the role of lacteals in the villi?
- (A) They absorb amino acids into the blood capillaries
- (B) They secrete mucus to protect the gut lining
- (C) They produce enzymes that digest proteins
- (D) They absorb fatty acids and glycerol into the lymph system
Show Answer
Answer: D – Fatty acids and glycerol pass into the lacteal in each villus, while glucose and amino acids pass into the blood capillaries.
Q25. Why are microvilli on the cells lining the small intestine important for absorption?
- (A) They secrete hydrochloric acid to kill bacteria
- (B) They contract to push food along the gut
- (C) They greatly increase the surface area available for absorption
- (D) They store bile until it is needed
Show Answer
Answer: C – Microvilli are tiny folds on the cell surface that, together with villi, give the small intestine a very large absorbing surface.
Q26. Most water is absorbed from which part of the digestive system?
- (A) The rectum only
- (B) The stomach, with some also absorbed from the mouth
- (C) The small intestine, with some also absorbed from the colon
- (D) The oesophagus, with some also absorbed from the stomach
Show Answer
Answer: C – Most water is absorbed in the small intestine, and the colon absorbs some of the remaining water, firming the faeces.
Q27. After absorption, amino acids are used in assimilation. Which use of amino acids is correct?
- (A) They are broken down to glucose for immediate energy only
- (B) They are built into new proteins needed by the body
- (C) They are stored in the gall bladder as bile
- (D) They are converted to starch for storage in muscles
Show Answer
Answer: B – Assimilation includes using absorbed amino acids to make the body’s own proteins for growth and repair.
Q28. A patient produces very little pancreatic juice. Which type of digestion would be most reduced?
- (A) Physical digestion of food in the mouth
- (B) Absorption of water in the colon
- (C) Chemical digestion of starch, proteins and fats in the small intestine
- (D) Egestion of undigested food from the rectum
Show Answer
Answer: C – Pancreatic juice supplies amylase, proteases and lipase to the small intestine, so all three kinds of chemical digestion would slow down.
Q29. Which sequence correctly summarises the fate of a starch meal?
- (A) Ingestion, chemical digestion to glucose, absorption in the small intestine, assimilation in cells
- (B) Absorption, ingestion, chemical digestion to glucose, assimilation in cells
- (C) Ingestion, absorption in the stomach, chemical digestion to amino acids, egestion
- (D) Ingestion, chemical digestion to glucose, absorption in the stomach, egestion
Show Answer
Answer: A – Starch is digested to glucose, absorbed through the small intestine into the blood, and then used by cells, for example in respiration.
Q30. Which nutrient, if missing from the diet, would most directly reduce the body’s ability to make new enzymes?
- (A) Protein, because enzymes are proteins built from amino acids
- (B) Fibre, because enzymes are made from roughage
- (C) Water, because enzymes are stored in water
- (D) Vitamin D, because enzymes contain vitamin D
Show Answer
Answer: A – Enzymes are proteins, so the body needs a supply of amino acids from dietary protein to build them.
Revisit any questions you missed, then test yourself again on the enzymes and the villi until each step feels secure.