Final answer:
The nucleus is the organelle surrounded by two phospholipid bilayers, which form the nuclear envelope that separates the nucleoplasm from the cytoplasm and regulates molecular traffic. Correct option is (B).
Step-by-step explanation:
The organelle that is surrounded by two phospholipid bilayers is the nucleus. The nuclear envelope, which encases the nucleus, is comprised of two lipid bilayers and is part of the endomembrane system, as it is continuous with the rough endoplasmic reticulum. This structure not only separates the nucleoplasm from the cytoplasm but also regulates the entry and exit of molecules in and out of the nucleus.
Other organelles like the mitochondria also have double membranes, which is significant to their functions, such as the production of ATP, thus dubbing them the 'power plants' of the cell.
The nucleus is surrounded by two phospholipid bilayers, known as the nuclear envelope or nuclear membrane. The nuclear envelope consists of an outer membrane and an inner membrane, with a space between them called the perinuclear space. The nuclear envelope plays a crucial role in maintaining the integrity of the nucleus and regulating the passage of molecules in and out of the nucleus.