Which term best describes the outer boundary that encloses the nucleus?

• A. Nuclear membrane/envelope
• B. Cell membrane
• C. Golgi apparatus
• D. Nucleolus

Answer: (A)

The boundary around the nucleus is called the nuclear envelope. It’s the outer membrane that encloses the genetic material and separates the nucleus from the cytoplasm, with two lipid bilayers and pores that regulate what goes in and out. This enclosure keeps the nuclear environment distinct and protects DNA while allowing transport of RNA and proteins through nuclear pores. The cell membrane surrounds the entire cell, not just the nucleus. The Golgi apparatus is a set of membrane-bound sacs involved in modifying and shipping proteins, located in the cytoplasm. The nucleolus is a region inside the nucleus where ribosomal RNA synthesis begins; it’s not a boundary.