Nucleoproteíns are synthesised in

The correct option is cytoplasm.

Nucleoproteins are conjugated proteins consisting of a protein linked to a nucleic acid (either DNA or RNA). Examples include histones, ribosomes, and transcription factors.

To understand why they are synthesized in the cytoplasm, let us look at the step-by-step biological process of protein synthesis:
1. Transcription: The genetic information for the protein component of nucleoproteins is stored in the DNA inside the nucleus. This DNA is transcribed into messenger RNA (mRNA) within the nucleoplasm.
2. Export of mRNA: The newly synthesized mRNA molecules must leave the nucleus. They travel through the nuclear pores of the nuclear envelope to enter the cytoplasm.
3. Translation: In the cytoplasm, ribosomes bind to the mRNA. Ribosomes translate the genetic code carried by the mRNA into a specific polypeptide chain (protein). Thus, all translation of nuclear-encoded proteins, including nucleoproteins, occurs on ribosomes located in the cytoplasm.
4. Import into the Nucleus: Once the protein component is synthesized in the cytoplasm, it must function inside the nucleus. These proteins contain specific nuclear localization signals (NLS) that allow them to be transported back across the nuclear envelope into the nucleoplasm, where they bind to nucleic acids to form functional nucleoproteins.

Therefore, even though nucleoproteins perform their primary functions inside the nucleus, their protein components are synthesized in the cytoplasm.