Question

select the two answers that are correct.
□ the cell membrane is composed of a bilayer of phosphoproteins, each of which contains a hydrophilic head and a hydrophobic tail.
□ the cell membrane is composed of a bilayer of phospholipids, each of which contains a hydrophilic head and a hydrophobic tail.
□ the hydrophilic head interacts with the external environment or the cytoplasm, and the hydrophobic tail interacts with other phospholipid tails within the cell membrane.
□ the cell membrane is composed of a single layer of phospholipids, each of which contains a hydrophilic head and a hydrophobic tail.
□ the hydrophilic head interacts with proteins embedded in the membrane, and the hydrophobic tail interacts with the external environment or the cytoplasm.

Explanation:

The cell membrane's basic structure is a phospholipid bilayer (not phosphoproteins or a single layer). Phospholipids have hydrophilic heads (water-interacting) facing aqueous environments (external or cytoplasm) and hydrophobic tails (water-avoiding) facing inward, interacting with other tails. These two statements align with the fluid mosaic model of the cell membrane.

Answer:

The cell membrane is composed of a bilayer of phospholipids, each of which contains a hydrophilic head and a hydrophobic tail.
The hydrophilic head interacts with the external environment or the cytoplasm, and the hydrophobic tail interacts with other phospholipid tails within the cell membrane.