If a bacterium cannot use citrate agar will not change its color (stays green). On the other hand, if bacteria have the ability to use citrate, the medium will change its color from green to blue.
This happens because citrate agar contains pH indicator such as bromothymol blue which transforms from green to blue in alkaline conditions.
The process that is directly responsible for the formation of the bud on the hydra is;
B - Mitosis
In my opinion, I think it would be granite rocks.
I believe the answer is D. The organisms would require an outlet for their waste.
