Final answer:
A cell's overall thickness affects its permeability by decreasing permeability as thickness increases (Option A). A thicker plasma membrane hinders diffusion, and a lower surface area-to-volume ratio in larger cells decreases efficiency in transport processes.
Step-by-step explanation:
The effect of a cell's overall thickness on its permeability is that as the cell's thickness increases, its permeability decreases. This is because a thicker plasma membrane presents a larger barrier for substances to cross.
The selective permeability of the plasma membrane is crucial for the survival of the cell, allowing necessary substances in while keeping harmful substances out.
The surface area to volume ratio also plays a critical role in the cell's efficiency; as a cell grows, its surface area-to-volume ratio decreases, which can limit diffusion if the plasma membrane does not have enough surface area to support the increased volume.
Eukaryotic cells have developed organelles and a sophisticated membrane system to maintain efficient transport and diffusion rates despite their larger sizes compared to prokaryotic cells.
The plasma membrane, being a phospholipid bilayer with embedded proteins, is designed to maintain a balance between the interior and exterior environments of the cell.
As such, any increase in a cell's thickness, specifically the thickness of the plasma membrane, affects the cell's permeability and overall ability to transport substances efficiently.
Hence, the correct answer is Option A.