Ribosome
A ribosome is a mixture of protein and RNA that starts being made in the nucleolus of a cell. The nucleolus is in the  nucleus. The nucleus is protected by the nuclear envelope, and lets things out through the nuclear pores. Ribosomes move from the nucleolus into the cytoplasm. Most ribosomes sit on the endoplasmic reticulum, but are also found throughout the cytoplasm.