A large polar molecule in the extracellular region can enter a cell by:Select one alternative:moving directly through the phospholipid bilayer of the plasma membrane.moving through a pore in the plasma membrane, created by connexin proteins.moving through the plasma membrane via exocytosis.moving through a carrier protein in the plasma membrane.

A large polar molecule in the extracellular region can enter a cell by moving through a carrier protein in the plasma membrane.

Here's the step-by-step process:

1. The large polar molecule approaches the plasma membrane of the cell.

2. The molecule cannot pass directly through the phospholipid bilayer of the plasma membrane because the interior of the membrane is hydrophobic and the molecule is polar.

3. The molecule also cannot enter the cell through a pore created by connexin proteins, as these pores are typically used for direct cell-to-cell communication.

4. Exocytosis is a process by which materials are exported out of the cell, not into the cell, so the molecule cannot enter the cell this way.

5. Instead, the molecule can bind to a carrier protein in the plasma membrane. These proteins are specifically designed to transport certain molecules across the cell membrane.

6. Once the molecule binds to the carrier protein, the protein changes shape and transports the molecule across the membrane and into the cell.

7. After the molecule has been transported, the carrier protein returns to its original shape, ready to transport another molecule.