Model of a typical animal cell. In the middle is the nucleus (blue, dimpled), inside of which is the nucleolus surrounded by chromatin fibres (red). Surrounding the nucleus is rough endoplasmic reticulum (red), with smooth endoplastic reticulum at lower right (yellow spots). Below the nucleus is the Golgi complex (yellow). Alsp present are mitochondria (red, peanut-shaped) and lysozymes (green pods). At upper left are centrioles (yellow, ridged).