Where are earthquakes most likely to take place?
(1) along the core-mantle interface
(2) where the composition of the Earth
tends to be uniform
(3) near the Earth's Equator
(4) near a fault zone

it has one origin of replication, but it proceeds in two directions - d)

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.