An important organelle is missing from this image of a eukaryotic cell undergoing protein synthesis. this organelle s not surrounded by a membrane but sits in the nucleus. it produces ribosomal subunits from proteins and ribosomal rna, which is exported into the cell proper. it is key to the process of protein synthesis taking place at ribosomes. what is this organelle? a) centriole b) centrosome c) mitochondria d) nucleolus

D.) Nucleolus

Explanation:

The nucleolus is a round body located inside the nucleus of a eukaryotic cell. It is not surrounded by a membrane but sits in the nucleus. The nucleolus makes ribosomal subunits from proteins and ribosomal RNA, also known as rRNA. It then sends the subunits out to the rest of the cell where they combine into complete ribosomes. Ribosomes make proteins; therefore, the nucleolus plays a vital role in making proteins in the cell.