Nuclear pores regulate transport between nucleus and cytoplasm.

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

Answer: (A)

Nuclear pores regulate transport between the nucleus and cytoplasm. These pores are large protein complexes that span the nuclear envelope and act as selective gates. They allow small molecules to diffuse but require transport receptors and energy-driven steps (via the Ran GTPase cycle) for larger cargo like proteins with a nuclear localization signal or RNA–protein complexes to move in or out. This setup keeps the nucleus protected while still permitting essential traffic, such as ribosomal subunits and mRNA export.

They are not storage sites for DNA—DNA is housed inside the nucleus as chromatin. They do not synthesize ribosomes; ribosome production occurs in the nucleolus within the nucleus and ribosomal subunits are assembled and exported. They do not generate energy; energy production occurs primarily in mitochondria.