2. what percentage of time has life existed on earth (round to the nearest whole numbe

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.

the main thing i would use is bricks because if there is a hurricane, there is a great possibility for the house to still stand. and i would also use plexiglass windows instead of regular windows because plexiglass isn't prone to breaking.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.

characteristics of hydrocarbons