Question

The salmon with the genetic abnormality that results in the blood and the water moving in the same direction through the gills, now swims into a sewer tank in which half the oxygen normally present has been replaced by CO2. Again assume the blood of the fish coming from the tissues has a PCO2 of 25 mm Hg just before it gets to the gill lamellae Draw a diagram showing the change in the partial pressure for CO2 in both the water and blood as it goes through the gill.

Answer 1

Answer :)

The CO2 content in sewer water is 50% of oxygen. It means the CO2 reaches 50% of the partial pressure of Oxygen. Therefore, the pCO2 level in this water is 50 mmHg while the pO2 is decreased to 50 mmHg from 100 mmHg in normal water. The impure blood of the salmon contains pCO2 of 25 mmHg that exceeds to 50 mmHg in the arteries. CO2 moves from higher to lower concentration. Therefore, blood in fish will become toxic for it.