By simulating conditions thought to have existed on the early Earth, Miller and Urey
found that these conditions could result in
the formation of

feral cats are estimated to eat tens of millions of native animals each night in australia

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.

d. groundwater flows through the subsoil and deposits minerals.