BREATHING AND EXCHANGE OF GASES
1. In a 400 metre race competition, Athira won the first place. Her friends commented that it is due to her high vital capacity.
a. What do you understand by the term vital capacity?
b. Suggest the ways to improve the vital capacity.
1. In a normal person expiratory reserve volume and residual volume were found to be 1000 ml and 1100 ml respectively.
a. Find out his functional residual capacity. (1)
b. How the functional residual capacity differs from the vital capacity? (1)
1. Observe the graph.
a. Identify the partial pressure of oxygen where 50% of saturation of Hb with oxygen. (½)
b. Mention the factors favourable for the formation of oxyhaemoglobin in alveoli. (1½)
1. The graph given below is the oxygen –haemoglobin dissociation curve. Observe the graph and answer the following questions.
a. Identify the PO2 where 90% haemoglobin saturation occurs. (½)
b. Write any three factors favorable for the formation of oxyhaemoglobin in alveoli. (1½)
1. Identify the two true statements from the statements given below and rewrite the two false statements correctly.
a. Pneumonia is a chronic disorder due to cigarette smoking.
b. Carbon dioxide combines with haemoglobin to form carbamino haemoglobin.
c. Respiratory rhythm is maintained by the respiratory centre in the heart.
d. Alveoli are the primary sites of exchange of gases. (2)
1. Prepare an equation for a chemical reaction using the following components.
Carbonic anhydrase, carbonic acid, water, carbon dioxide (1)
2. Observe the figure and answer the questions.
a. What is the partial pressure of oxygen in the alveolar capillary? (½)
b. Name the biological principles involved in the exchange of gases in the above structure. (½)
c. What happen when partial pressure of oxygen becomes same in the alveoli and alveolar capillary? (1)