Which of the following pair lack the unit membrane?

Cell organelles like ribosomes and nucleolus lack the unit membrane. Ribosomes are found individually in the cytoplasm and also line the membranes of the rough endoplasmic reticulum. It is composed of RNA and ribosomal protein. Nucleolus is a part of nucleus and characterized by the absence of limiting membrane, presence of chromatin and granules and fibrils of RNA and proteins.