An electron micrograph of a longitudinal thin section of a dividing Escherichia coli bacterium. The centrally located nucleoid is prominent. Image made available by James D. Jamieson and the Departmen...

Figures 228 (upper) and 229 (lower) from Chapter 7 (Mitochondria) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A mitochondrion from rat adrenal tissue grown in vitro shows an unusually high number of...

Transmission electron micrograph of a thin section through the bacterium Diplococcus pneumoniae. The fibrous nucleoid is centrally located, surrounded by cytoplasm containing numerous ribosomes.

Transmission electron micrograph of a thin section through the bacterium Diplococcus pneumoniae in the process of division. The fibrous nucleoids are seen in the center of the two daughter cells, surr...

Figures 226 (upper) and 227 (lower) from Chapter 7 (Mitochondria) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Examples of mitochondrial DNA from a plant cell (Vicia faba), and from the snake adrena...

Mitochondria of Vorticella convallaria like other ciliates, have tubular cristae arising from their inner membranes. However, they also have a bundle of filaments (DNA?) that extend through the center...

Mitochondria of Vorticella convallaria like other ciliates, have tubular cristae arising from their inner membranes. However, they also have a bundle of filaments (DNA?) that extend through the center...