NUMS — Medical & Dental Entry Test

NUMS Biology — Digestion, Gaseous Exchange and Transport (Set 2)

Take the NUMS Biology — Digestion, Gaseous Exchange and Transport (Set 2): 30 multiple-choice questions (40 minutes) with instant scoring and a full…

What this test covers

30 NUMS Biology

Sample questions with answers

The first 5 questions of this test, with the correct answer and explanation.

Q1. A person chews a piece of bread for several minutes and notices it begins to taste sweet. This is because:
- A. Bile converts starch to sugar
- B. Salivary amylase hydrolyses starch to maltose ✓
- C. Pepsin breaks proteins into glucose
- D. Lipase digests fats into sugars
Answer: B. Salivary amylase hydrolyses starch to maltose
Explanation: Salivary amylase (ptyalin) begins starch digestion in the mouth, producing maltose, which tastes sweet.
Q2. The parietal (oxyntic) cells of the gastric glands secrete:
- A. Mucus only
- B. Gastrin and secretin
- C. Hydrochloric acid and intrinsic factor ✓
- D. Pepsinogen and rennin
Answer: C. Hydrochloric acid and intrinsic factor
Explanation: Parietal cells produce HCl and intrinsic factor; chief cells secrete pepsinogen and goblet/mucous cells secrete mucus.
Q3. After surgical removal of a large part of the stomach, a patient develops pernicious anaemia. The cause is lack of:
- A. Gastrin needed to make red cells
- B. Intrinsic factor needed to absorb vitamin B₁₂ ✓
- C. Pepsin needed to absorb iron
- D. Bile needed to absorb folic acid
Answer: B. Intrinsic factor needed to absorb vitamin B₁₂
Explanation: Intrinsic factor from parietal cells binds vitamin B₁₂ for absorption in the ileum; B₁₂ deficiency impairs red-cell production.
Q4. The wave-like muscular contractions that push food along the oesophagus are called:
- A. Peristalsis ✓
- B. Segmentation
- C. Emulsification
- D. Chyme
Answer: A. Peristalsis
Explanation: Peristalsis is coordinated contraction of circular and longitudinal muscles moving food along the alimentary canal.
Q5. Trypsin is secreted as trypsinogen. Once some trypsin forms, it activates more trypsinogen. This is an example of:
- A. Autocatalysis (positive feedback) ✓
- B. Emulsification
- C. Negative feedback
- D. Competitive inhibition
Answer: A. Autocatalysis (positive feedback)
Explanation: Trypsin catalyses the activation of its own precursor, so activation accelerates itself; enterokinase starts the process.

The other 25 questions

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Q6. A fatty meal enters the duodenum. Which hormone is released that causes the gall bladder to contract and the pancreas to secrete enzyme-rich juice?
- A. Secretin
- B. Insulin
- C. Cholecystokinin (CCK)
- D. Gastrin
Q7. Gastrin is released from the stomach wall when food arrives. Its main effect is to:
- A. Stimulate insulin release
- B. Inhibit stomach emptying
- C. Stimulate secretion of gastric juice
- D. Release bile
Q8. Glucose is absorbed from the ileum into epithelial cells along with sodium ions via a symporter. Energy for this uptake comes indirectly from:
- A. Osmosis of water into the cell
- B. Simple diffusion of glucose
- C. The Na⁺/K⁺ pump keeping cell Na⁺ concentration low
- D. Bile salts
Q9. Inside each villus, fats are absorbed mainly into the:
- A. Goblet cells
- B. Blood capillaries
- C. Lacteal
- D. Hepatic artery
Q10. Absorbed glucose and amino acids from the intestine are first carried to the liver by the:
- A. Hepatic vein
- B. Hepatic portal vein
- C. Inferior vena cava directly
- D. Hepatic artery
Q11. A patient's skin and eyes turn yellow because a gallstone blocks the bile duct. The yellow colour is due to accumulation of:
- A. Urea from amino acids
- B. Bile salts from cholesterol
- C. Carotene from the diet
- D. Bilirubin from breakdown of haemoglobin
Q12. Lack of dietary fibre most commonly leads to:
- A. Diarrhoea
- B. Constipation
- C. Jaundice
- D. Peptic ulcer
Q13. The C-shaped cartilage rings of the trachea are important because they:
- A. Contract to push air into lungs
- B. Allow gas exchange
- C. Keep the airway open during pressure changes in breathing
- D. Produce mucus to trap dust
Q14. A person has a tidal volume of 500 cm³ and breathes 12 times per minute. Of each breath, 150 cm³ stays in the dead space. What is the alveolar ventilation per minute?
- A. 4200 cm³
- B. 6000 cm³
- C. 1800 cm³
- D. 7800 cm³
Q15. The volume of air that remains in the lungs even after the most forceful expiration is the:
- A. Vital capacity
- B. Residual volume
- C. Inspiratory reserve volume
- D. Tidal volume
Q16. At high altitude, a mountaineer's body produces more red blood cells over several weeks. The hormone driving this response is:
- A. Thyroxine from the thyroid
- B. Adrenaline from the adrenal medulla
- C. Aldosterone from the adrenal cortex
- D. Erythropoietin from the kidneys
Q17. The enzyme in red blood cells that rapidly converts CO₂ and water into carbonic acid is:
- A. Carbonic anhydrase
- B. Carboxypeptidase
- C. Catalase
- D. Cytochrome oxidase
Q18. Myoglobin in muscle has a dissociation curve far to the left of haemoglobin. This means myoglobin:
- A. Carries mainly CO₂
- B. Releases oxygen easily at high pO₂
- C. Holds oxygen tightly and releases it only when muscle pO₂ is very low
- D. Cannot bind oxygen at all
Q19. Asthma attacks make breathing difficult mainly because:
- A. Smooth muscle in bronchiole walls contracts, narrowing the airways
- B. The diaphragm becomes paralysed
- C. Haemoglobin cannot bind oxygen
- D. Alveoli fill with bacteria
Q20. Tuberculosis is caused by:
- A. Mycobacterium tuberculosis, a bacterium
- B. A protozoan spread by mosquitoes
- C. A fungus inhaled with dust
- D. A virus that attacks alveoli
Q21. During ventricular systole, the semilunar valves open when:
- A. Pressure in the ventricles exceeds pressure in the aorta and pulmonary artery
- B. Pressure in the atria exceeds ventricular pressure
- C. The SA node fires
- D. The ventricles begin to relax
Q22. A person has a heart rate of 75 beats per minute and a stroke volume of 70 cm³. What is the cardiac output?
- A. 1.45 dm³ per minute
- B. 7.5 dm³ per minute
- C. 5.25 dm³ per minute
- D. 52.5 dm³ per minute
Q23. On an electrocardiogram (ECG), the QRS complex represents:
- A. Repolarisation of the ventricles
- B. Closure of the AV valves only
- C. Depolarisation of the ventricles
- D. Depolarisation of the atria
Q24. Veins in the legs contain valves. Their main function is to:
- A. Allow gas exchange
- B. Increase blood pressure
- C. Prevent backflow of blood
- D. Pump blood to the heart
Q25. Arteries have a thicker layer of elastic tissue than veins. This allows arteries to:
- A. Prevent backflow with valves
- B. Hold most of the blood volume
- C. Stretch and recoil, smoothing the pulsatile flow from the heart
- D. Exchange materials with tissues
Q26. At the venous end of a capillary, fluid returns to the blood mainly because:
- A. Red cells actively pump water in
- B. The hydrostatic pressure is higher than at the arterial end
- C. The capillary wall becomes impermeable
- D. The osmotic pressure of plasma proteins exceeds the lower hydrostatic pressure
Q27. Which blood cells are most numerous in a normal sample of human blood?
- A. Erythrocytes
- B. Platelets
- C. Lymphocytes
- D. Neutrophils
Q28. Vitamin K deficiency increases bleeding time because vitamin K is needed for:
- A. Synthesis of prothrombin and other clotting factors in the liver
- B. Production of red blood cells
- C. Making platelets in the spleen
- D. Conversion of fibrinogen to glucose
Q29. Root pressure, which can be seen as guttation drops on grass leaves in the early morning, results from:
- A. Translocation of sucrose in phloem
- B. Transpiration pull from leaves
- C. Evaporation from the roots
- D. Active pumping of ions into xylem, drawing water in by osmosis
Q30. Water moving through the cell walls and intercellular spaces of root cortex, without crossing membranes, is using the:
- A. Symplast pathway
- B. Apoplast pathway
- C. Vacuolar pathway
- D. Phloem pathway