Final answer:
The transport of molecules across the membrane and the regulation of cell shape and movement can still occur even if the plasma membrane lacks specialized membrane proteins. Te correct answer is 1) Transport of molecules across the membrane and 2) Cell recognition and signaling.
Step-by-step explanation:
The plasma membrane, also known as the cell membrane, has several functions.
While specialized membrane proteins play a crucial role in many of these functions, there are some roles that the plasma membrane can still perform even if these proteins are lacking.
The roles of the plasma membrane that can occur without specialized membrane proteins include:
Transport of molecules across the membrane: The plasma membrane itself is selectively permeable and allows some molecules to freely enter or leave the cell without the assistance of specialized proteins.
Regulation of cell shape and movement: The plasma membrane provides a barrier that helps maintain cell shape and allows cells to move by changing their shape, even without specialized membrane proteins.
Therefore, the correct answer is 1) Transport of molecules across the membrane and 2) Cell recognition and signaling.