-Large polar molecule are list likely to cross the phospholipid bilayer.
Explanation;
-A large polar molecule would be the least likely to passively diffuse through a plasma membrane without the help of a transport protein. Both its size and the hydrophobic interior of the membrane would restrict it.
-Only small uncharged molecules can diffuse freely through phospholipid bilayers. Small nonpolar molecules, such as O2 and CO2, are soluble in the lipid bilayer and therefore can readily cross cell membranes.
-Ions and large polar molecules cannot pass through the lipid bilayer. But more specifically, whether a molecule can pass through the membrane depends on its size and its electrical nature.
A<em> fish ladder</em> is also known as fish steps, fish pass or fishway.
It is built around waterfalls, dams and locks.
The purpose of building a fish ladder is to<em> facilitate the natural migration of diadromous fishes.</em>
A fish ladder helps the fish to pass through the barriers by leaping up or swimming through the low steps of the ladder and reach into the water on the other side.
Since, without the fish ladder the barriers will not allow the migration of fishes, it is essential to be built around the dams, waterfalls and locks.