Phenol red is used as the indicator for the Urea Medium because the indicator detects the formation of ammonia caused by the hydrolysis of urea done by the bacteria. Bromothymol blue is used in Simmons Citrate Agar because it effectively indicates the formation of carbonates formed by the consumption of citrate.
D. The octupus population would decrease.
This is because if more sharks were in the ecosystem than they would feed on more octopus, decreasing the population of them.
The answer would be 36, you just fill in what you know and solve the problem.
