The doses of various drugs that are typically prescribed for schizophrenia are closely related to the strength of what effect]

The effect is the blockage of DA receptors.  Constant use of large doses of amphetamine or cocaine can lead to a behavioral condition similar to schizophrenia.  Researches today findings suggest that compared to normal people, people with schizophrenia have More Glutamate Receptors.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in