The photo in (a) shows the tall cylindrical microscope, which has a binocular eyepiece near its base. The microscope stands on the bench and the images are displayed on computer screens beside it. The electron micrograph in (b) shows a roughly spherical cell with its darkly staining (electron-dense) nucleus toward the left. Within the nucleus are several large and irregularly-shaped, pale (electron-lucent) areas, which are the nucleoli. In the cytoplasm, to the right of the nucleus, are several mitochondria which have been sectioned in different planes; the internal membranes of the organelle appear dark against the paler matrix. Also present in the cytoplasm are the fluid-filled vesicles and flattened sacs of the Golgi apparatus.