Fish gulps water through mouth and forces it between the gills. The oxygen in it gets diffused into the blood circulating in gills and carbon dioxide in the bloodstream diffuses into the water which is carried out through a gap between fish’s body and the gill cover.
1. Which process is being tested in the activity? 2. What is the result of the activity? Give reasons. 
1.In which jar, will the amount of CO2 be the highest and why? 2. In which jar, will the amount of CO2 be the lowest and why?