There are two main types of cells: eukaryotic cells which include plant, animal, fungi and protist cells, and prokaryotic cells which are bacteria and archaea. All cells share some common features like a cell membrane, cytoplasm and nucleus, while plant cells also contain chloroplasts, a vacuole and cell wall. Cells can be specialized to perform particular functions, such as leaf cells, sperm cells, red blood cells and root hair cells. Some specialized cell types include nerve cells which carry nerve impulses and egg cells which join with male cells during reproduction.