A lizard was placed in a chamber with a constant flow of air. The temperature of the chamber
was varied between 25 °C and 10 °C. Apart from temperature and time, all other variables were
kept constant.
The carbon dioxide concentrations in the air leaving the chamber are shown in the graph.
Which of the following statements is/are correct?
1 Between 25 °C and 10 °C the respiration rate of the lizard is inversely proportional to
the environmental temperature.
2 The data demonstrates that the lizard is only respiring aerobically.
3 The carbon dioxide could be detected by passing the air leaving the chamber

Answer:

9) D

Statement 1 is wrong because as temperature decreased, the carbon dioxide concentration also decreased which meant that the lizard’s respiratory rate also decreased. So the respiration rate of the lizard is NOT inversely proportional to the environmental temperature.

Statement 2 is wrong. We cannot determine whether the lizard is only respiring aerobically. It may also be respiring anaerobically.

Statement 3 is correct. The limewater test is a test for carbon dioxide and hence it can detect carbon dioxide in the air leaving the chamber.