(a) Diagram 6.1 shows a gaseous exchange in the alveolus.
Diagram 6.1
Explain how oxygen is transported to the body tissues for cellular respiration. [4 marks]
(b)
Based on the statement above, suggest and explain how to keep our lungs healthy. [6 marks]
(c) Diagram 6.2.1 and 6.2.2 show the respiratory organ from two different organisms.
Explain similarities and differences in structures of the respiratory organ between the two organisms. [10 marks]
Answer:
(a)
– Oxygen gas in the alveoli is at higher partial pressure / higher concentration than in blood.
– Oxygen molecules diffuse across epithelium of alveoli and blood capillaries into blood.
– Oxygen binds with haemoglobin in the red blood cells / erythrocytes to form oxyhaemoglobin.
– The oxygenated blood is then transported from the lungs to cells of body tissues.
– In the tissues, oxyhaemoglobin dissociates into oxygen and haemoglobin.
– Oxygen diffuses down a concentration gradient across the epithelia of blood capillaries into the cells of body tissues.
(b)
(c)
