Biological theories that focus on and chemical precursors to crime, which cannot explain why certain kinds of crime are more likely to occur in certain parts of the country, in particular types of communities, and among members of specific subcultures rather than in others

the answers are a and c

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.