Color enhanced Transmission Electron Micrograph (TEM) section of a young cell from the root-tip meristem of Arabidopsis thaliana: the nucleus (pink) contains a nucleosis (dark) and granular nucleoplasm but very little obvious heterochromatin; the nuclear envelope consists of two membranes traversed by nuclear pores; the cytoplasm contains mitochondria (blue), proplastids (juvenile chloroplasts, without developed thylakoid systems (green), Golgi bodies (dictyosomes, with up to six cisternae, red), large ribosomes, spares endoplasmic reticulum with ribosomes on the matrical surfaces, large and small vacuoles (spaces with reticulate contents) and the plasmalemma (cell membrane); external to the latter lies the cell wall, showing something of its fibrillar cellulosic construction (brown).