The answer you are looking for is called Serotonin. Please put this as the brainiest answer thank you and hope this helped.
Giraffe is the animal with bottom teeth.
Answer:
The color of the birdfeeders
Explanation:
Independent variable is the variable in the experiment that is changed, so the only thing changed in this experiment is the colors of the bird feeders
An enzyme, it catalyzes the reaction to convert carbon dioxide into carbonic acid
