Question

which of the following is a phospholipid bilayer which separates the contents of a cell from the outer environment?
cytoplasm
plasma membrane
chloroplast
mitochondria

Explanation:

• Cytoplasm: It is the jelly - like substance within the cell, not a membrane.
• Plasma membrane: Composed of a phospholipid bilayer, it acts as a barrier separating the cell's contents from the external environment.
• Chloroplast: An organelle involved in photosynthesis, not the main boundary - defining structure.
• Mitochondria: An organelle for energy production (ATP synthesis), not the boundary - defining structure.

Answer:

Plasma membrane