(Solved): A(n) allows some substances to move freely into and out of a cell by simple diffusion while it w ...

A(n)

allows some substances to move freely into and out of a cell by simple diffusion while it will always exclude some substances from crossing. However, some substances that cannot cross by simple diffusion can pass through with the help of either active or passive transport proteins. selectively permeable membrane eytosol impermeable membrane eytoskeleton