What does selective permeability of the cell membrane allow?

Selective permeability of the cell membrane refers to the ability of the membrane to regulate which substances can pass in and out of the cell. This property is crucial for maintaining homeostasis within the cell, allowing essential nutrients such as food and oxygen to enter while keeping out harmful substances.

The cell membrane is composed of a phospholipid bilayer with embedded proteins that create channels and receptors, allowing certain molecules to selectively pass through. This selectivity is vital for the cell's function and survival, as it ensures that the necessary materials for cellular processes are available while protecting against toxins and pathogens.

The correct response emphasizes the membrane's role in permitting only specific substances entry, highlighting the distinction between what can and cannot cross the membrane. This selective nature is fundamental in processes like nutrient uptake and waste removal, which are critical for the cell's overall health and function.