The part of a cell that protects it from its environment is the...?

This would be the cell membrane or in a plant cell, the cell wall.

i have to do a research project on dolphins

The part of a cell that protects it from its environment is the cell membrane. It acts as a barrier, regulating the movement of substances in and out of the cell. To understand how the cell membrane provides this protection, we need to take a closer look at its structure.

The cell membrane consists of a phospholipid bilayer. Each phospholipid molecule has a hydrophilic (water-loving) head and two hydrophobic (water-fearing) tails. The hydrophilic heads face outward, interacting with the watery environment both inside and outside of the cell. The hydrophobic tails face inward, creating a nonpolar region in the middle of the membrane.

This arrangement of phospholipids forms a semi-permeable barrier. It allows certain molecules, such as oxygen and carbon dioxide, to pass through easily due to their small size and nonpolar nature. However, larger molecules and charged particles require other mechanisms, such as protein channels or transporters, to cross the membrane.

In addition to protection, the cell membrane also plays a crucial role in cell communication and recognition. It contains various proteins, receptors, and markers that enable cells to interact with their environment and other cells.

In summary, the cell membrane acts as a protective barrier that regulates the movement of substances in and out of the cell, allowing for proper functioning and survival of the cell.