The figure shows a healthy lung and a diseased lung.

(a) Identify the disease and the affected part of the lung.
The disease is emphysema, and the affected part is the alveoli.

(b) How does part B show structural variation from part A?
In part B (diseased lung), the alveoli are damaged and enlarged, reducing their surface area for gas exchange. The walls of the alveoli may be ruptured, leading to air trapping and inefficient oxygen exchange.

(c) Write any two symptoms of the disease.
Two common symptoms of emphysema are:

  1. Shortness of Breath (Dyspnea): Emphysema damages the air sacs (alveoli) in the lungs, which reduces the surface area for gas exchange. This makes it harder for the lungs to take in oxygen and expel carbon dioxide, leading to difficulty breathing, especially during physical activity.

  2. Chronic Cough: Emphysema often leads to persistent coughing as the body attempts to clear mucus from the lungs. This can be accompanied by sputum (mucus) production and is often mistaken for a smoker’s cough in individuals who smoke or have smoked in the past.

Related Questions:

  1. Name the structure through which the exchange of gases can take place in plants.
  2. Name the ways through which a plant can obtain oxygen.
  3. Why should one not sleep under a tree at night?
  4. Why would very wet soil be dangerous to plants
  5. Why do plants not need a specialized respiratory system?
  6. How does the exchange of gases take place in alveoli?
  7. What is the effect of exercise on the rate of breathing?
  8. Compare inspired air and expired air.
  9. How do viral infections like COVID-19 affect bronchi?
  10. What is the importance of breathing in fresh air?
  11. What is the importance of keeping the nasal and oral cavity clear?
  12. Differentiate between:
  13. Breathing through the nose is healthier than breathing by mouth. Why?
  14. What are the conditions necessary for efficient gaseous exchange between an organism and the environment?
  15. Describe the effects of cigarette smoking on the inner walls of the trachea of human beings.
  16. The diagram shows the percentage of gases in inspired and expired air.