This large, fan-shaped muscle of the upper chest is the prime mover of arm flexion.
pectoralis major
external oblique
serratus
anterior deltoid

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.

when it is at an intermediate population density

haha

it's made from mineral oil

a population evolve