Cytoplasmic breakdown is also orderly. The cytoplasm condenses (as reflected by a darkening of the cell in electron micrographs, see Fig. 2), and subsequently the cell shrinks in size, while the plasma membrane remains intact. Condensation of the cytoplasm can be associated with the formation of translucent cytoplasmic vacuoles derived from the endoplasmic reticulum or the Golgi apparatus. It is thought that the mitochondria are normal and are required for apoptosis.