Final answer:
The organelle that acts as a barrier between the cytoplasm and the extracellular environment is the lipid bilayer membrane, also known as the cell membrane or plasma membrane.
Step-by-step explanation:
The Organelle Separating Cytoplasm from the Extracellular Environment
The organelle that separates the cytoplasm from the extracellular environment is the lipid bilayer membrane. This membrane is also known as the cell membrane or plasma membrane. It is crucial in maintaining homeostasis by regulating the passage of substances in and out of the cell. The phospholipid bilayer that constitutes the cell membrane has distinct hydrophobic tails and hydrophilic heads, providing the cell with a selective barrier against the extracellular environment.
The nucleus, which contains most of the genetic material of the cell, is surrounded by its own double membrane called the nuclear membrane, which separates it from the cytoplasm. However, when considering the entire cell, it is the plasma membrane that provides the primary separation from the external environment.
Other cell structures such as ribosomes and lysosomes are contained within the cytoplasm and do not provide this separation. While DNA is crucial for genetic information, it is not an organelle and does not separate the cell from its surroundings. The answer to the question is option E - Lipid bilayer membrane.