- The primary function of nuclear pores is to facilitate the exchange of materials between the nucleus and the cytoplasm.
- These pores are large protein complexes embedded in the nuclear envelope, which is the double membrane surrounding the nucleus.
- They regulate the transport of molecules such as RNA and proteins, allowing essential substances like messenger RNA (mRNA) and ribosomal subunits to exit the nucleus, while permitting the entry of proteins and nucleotides needed for nuclear functions.

It is important to note that nuclear pores do not synthesize ribosomal RNA (Option 2), which occurs within the nucleolus, nor do they primarily provide structural support to the nuclear envelope (Option 3). Additionally, DNA replication (Option 4) takes place inside the nucleus but is not a function of the pores themselves.

In summary:
- Nuclear pores act as gateways for molecular trafficking.
- They maintain selective exchange, ensuring cellular function and genetic regulation.
- Their structure and function are critical for communication between the nucleus and cytoplasm.