Which gas found in water do fish, clams, and snails use in order to breathe?

What is the best-known carbohydrate?

Photosynthesis uses co2 and cellular respiration produces co2. we call the point when the two processes are in balance--when there is no net production of co2--the compensation point. how might you limit one of the processes in order to achieve a compensation point?

Up to what percentage of the world's flora consisted of cycads during the triassic period? 100% 75% 50% 20%