Prokaryotes – Parts of the Cell Nucleoid Reproduction – DNA Ensures offspring will be similar to parent Homeostasis Cell Wall Keeps inside cell safe Penicillin breaks some bacteria cell wall Flagellum Respond to Stimulus Lets them move in their environment Pilus Respond to Stimulus Ribosomes Builds Protein and Repairs Cell Plasmid Assists with Genetic Variation Cytoplasm Homeostasis , uses energy to facilitate chemical reactions Capsule Prevents cell from being eaten by other cells Prevents Water Loss Plasma Membrane Allows nutrients into the cell and waste out