Serotonin is derived from which molecule?
A. Melatonin
B. Dopamine
C. GABA
D. Tryptophan

Punctuated equilibrium verses gradualism have long been contested as ways in which species evolve. choose the best evidence for gradualism.

Aplant may open end close its stomata to prevent excess water loss and maintain

Which statement is the best summary of the model? a-a series of aerobic and anaerobic reactions take place in cells b- the sun's energy moves through trophic levels in a food chain c-light energy is converted into stored chemical energy plants.d- food molecules are broken down in the cells if living things.