Answer: Ribosomes
Step-by-step explanation:
Eukaryotic cells contain membrane-bound organelles, for example animal cells and plant cells. While prokaryotic cells don't, for example bacteria.
Since chloroplasts, mitochondria and endoplasmic reticulum are membrane-bound organelles, which meas that these organelles are surrounded by a phospholipid bilayer, they are only found in eukaryotes.
Endoplasmic reticulum is responsible for protein folding, modification and transport. Chloroplast is responsible for photosynthesis in plants, and mitochondria is responsible for cellular respiration. And, ribosomes is the organelle where protein synthesis takes place, and this happens in both Eukaryotic and Prokaryotic cells.