Question

thyroid hormones
thyroxine (t₄) triiodothyronine (t₃)
○ they do not require a carrier protein to be transported in the plasma.
○ they dissolve into water.
○ they are water soluble.
○ they can cross a cell membrane via simple diffusion.

Explanation:

Thyroid hormones (T₃, T₄) are lipid - soluble (hydrophobic) and non - polar. Lipid - soluble molecules can cross the cell membrane via simple diffusion as the cell membrane is mainly composed of lipids. They are not water - soluble, do not dissolve in water easily, and require carrier proteins in the plasma for transport. So the correct statement is that they can cross a cell membrane via simple diffusion.

Answer:

The option "THEY CAN CROSS A CELL MEMBRANE VIA SIMPLE DIFFUSION."