Question

ability of non - polar steroids to pass through the phospholipid bilayer (b1.1.13)
list the types of molecules that can freely cross the phospholipid bilayer

Explanation:

Small, non - polar molecules can freely cross the phospholipid bilayer due to the hydrophobic nature of the lipid tails in the bilayer. Examples include oxygen, carbon dioxide, and small hydrophobic molecules like steroids.

Answer:

Small non - polar molecules (such as oxygen, carbon dioxide, non - polar steroids), and very small uncharged polar molecules (like water to a limited extent) can freely cross the phospholipid bilayer.