AnswerExplanation:
The nucleolus is a region of the nucleus where ribosomal RNAs are synthesized.
Ribosomes are protein synthesis factories made from the ribosomal RNAs that are synthesized in the nucleolus and ribosomal proteins.
Sometimes, ribosomes are found free in the cytoplasm, other times they are attached to the endoplasmic reticulum, forming the rough endoplasmic reticulum. The rough endoplasmic reticulum is the site of protein synthesis for proteins that are to be secreted from the cell