What do nuclear pores do?

• A. They store DNA
• B. They regulate transport between the nucleus and cytoplasm
• C. They synthesize lipids
• D. They produce energy

Answer: (B)

Nuclear pores act as gateways that regulate transport between the nucleus and cytoplasm. They are large protein complexes that span the nuclear envelope, forming channels through which small molecules can diffuse, while larger proteins and RNAs are moved in and out by selective, receptor‑mediated transport systems. The process relies on transport receptors (importins and exportins) and the Ran GTPase cycle to provide directionality and energy for moving cargo such as transcription factors into the nucleus, ribosomal subunits out to the cytoplasm, and various RNA species. This careful regulation keeps the nuclear and cytoplasmic environments distinct and is essential for proper gene expression, RNA processing, and ribosome assembly. They do not store DNA, synthesize lipids, or produce energy.