2.5.2 Cystic fibrosis and the gaseous exchange, digestive and reproductive systems Quiz: Pearson Edexcel Biology A (Salters-Nuffield), Unit 2

The 20 questions

1. In the gaseous exchange system, what is the main effect of thick mucus caused by CF?

   • It blocks airways and traps bacteria
   • It increases the surface area of the alveoli, which speeds up oxygen uptake
   • It prevents carbon dioxide from leaving the blood in the capillaries
   • It widens the bronchioles so that air flows more easily into the lungs

2. In the digestive system, what happens to digestive enzymes in cystic fibrosis?

   • They are made in the stomach instead of the pancreas, altering their pH optimum
   • They are produced in excess and absorbed into the bloodstream without digesting food
   • They cannot reach the small intestine because the pancreatic ducts are blocked by thick secretions
   • They become more effective because the secretions are more concentrated

3. In males with cystic fibrosis, why are they often infertile?

   • The acrosome fails to form, so the sperm cannot fertilise the egg
   • Sperm have no flagella and cannot swim to the egg
   • The testes fail to produce any testosterone during puberty
   • The vas deferens is often absent or blocked

4. What reproductive problem is associated with CF in females?

   • Thick cervical mucus that can make it harder for sperm to pass into the uterus
   • Failure of the placenta to form, so pregnancy is never possible
   • Overproduction of oestrogen that prevents ovulation completely
   • Absence of ovaries so that no eggs are released during the menstrual cycle

5. Which organ system is most affected by lung infections in cystic fibrosis?

   • The skeletal system
   • The gaseous exchange system
   • The nervous system
   • The excretory system

6. Why does CF lead to malabsorption of fats?

   • The small intestine lacks villi so absorption cannot occur
   • Pancreatic lipase cannot reach the intestine
   • Fat-soluble vitamins are destroyed by stomach acid before they are absorbed
   • Bile is produced in excess and forms a solid barrier in the stomach

7. How does CF affect the liver in some patients?

   • The liver filters red blood cells and removes haemoglobin
   • Bile ducts can become blocked, which may contribute to liver damage
   • The liver stops making bile altogether, causing jaundice in every patient
   • The liver produces excess insulin and causes hypoglycaemia

8. Which combination of systems is affected by the CFTR mutation in cystic fibrosis?

   • Nervous, endocrine and immune systems
   • Gaseous exchange, digestive and reproductive systems
   • Skeletal, muscular and circulatory systems
   • Excretory, integumentary and lymphatic systems

9. A patient with CF has a blocked pancreatic duct. Which statement about the consequences is correct?

   • Bile is prevented from entering the small intestine, so no digestion of carbohydrate occurs
   • Insulin production rises sharply, causing excess glucose in the urine
   • Lipase and protease cannot enter the duodenum, so fat and protein digestion are impaired
   • Amylase is blocked, so starch is digested only in the stomach

10. A man with CF is infertile. Which structure is most directly responsible for this?

    • The duodenum
    • The cervix
    • The vas deferens
    • The bronchioles

11. Why do people with CF often have a higher risk of lung infections?

    • Their white blood cells are absent from the respiratory tract
    • Mucus traps bacteria in the airways and is not cleared effectively by cilia
    • The alveoli are much larger, making them easy targets for infection
    • The trachea is reduced in size and cannot filter air

12. Which symptom would be expected in a child with CF from pancreatic insufficiency?

    • Excessive sweating and low blood sodium only
    • Swelling of the joints with raised uric acid
    • Increased appetite with normal stool
    • Poor weight gain and fatty, bulky stools

13. In the respiratory system, what effect does thick mucus have on ciliated epithelial cells?

    • It stops them from producing mucus altogether
    • It makes them produce chloride ions in greater quantity
    • It increases their beat frequency to remove mucus faster
    • It reduces their ability to move mucus up and out of the airways

14. Which description best explains why CF affects the digestive system?

    • The stomach cannot secrete hydrochloric acid, so proteins remain undigested
    • The CFTR channel is absent from cells lining the pancreatic ducts
    • The gut microbiome is destroyed by antibiotics, so digestion fails
    • Nerves that control peristalsis are damaged, stopping food movement

15. A CF patient develops recurrent chest infections. Which is the most likely underlying cause?

    • Overactive immune system attacking the lungs
    • Failure of the diaphragm to contract
    • Persistent mucus obstruction and bacterial colonisation of the airways
    • Excess fluid in the pleural cavity from a heart defect

16. Which statement about digestive enzymes is correct in healthy individuals?

    • Pancreatic enzymes travel through the pancreatic duct into the duodenum
    • Pancreatic enzymes are secreted directly into the blood
    • Enzymes are produced in the small intestine and enter the oesophagus
    • Enzymes are secreted from the liver into the stomach

17. Why is CF associated with a higher risk of intestinal blockage in newborns?

    • Thick secretions can block the intestine, for example meconium ileus
    • Excess milk is produced and blocks the oesophagus
    • The intestine grows too quickly and folds over itself
    • Bacteria in the gut produce gas that inflates the intestine

18. Which factor best explains the reduction in fertility in women with CF?

    • Production of abnormal eggs that cannot be fertilised
    • Thick cervical mucus that may hinder sperm movement, along with other effects of chronic illness
    • Failure of ovulation in every cycle
    • Absence of the uterus, so implantation is impossible

19. Why is the sweat chloride test used when diagnosing cystic fibrosis?

    • Sweat contains CFTR protein, which is measured directly in a sample
    • Healthy people produce much more sweat, so a high volume indicates a healthy result
    • Sweat glucose rises in CF, so a sugar reading identifies the condition
    • Sweat chloride is raised in CF because the defective CFTR channel fails to reabsorb chloride from sweat ducts

20. A patient with CF takes pancreatic enzyme supplements with meals. What is the purpose of this treatment?

    • To replace the missing digestive enzymes so that food can be broken down and absorbed
    • To replace chloride ions lost through sweat during exercise
    • To stimulate insulin release and lower the blood glucose concentration
    • To thin the mucus in the lungs by breaking down protein in the airways

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