Fig. 1 Cultured HeLa cells have been stained with Hoechst turning their nuclei blue. The central and rightmost cells are in interphase, so the entire nuclei are labeled. The cell on the left is going through mitosis and its DNA has condensed (source: Wikipedia)

Fig. 2 (a) Transmission electron micrograph of thin section of Gemmata obscuriglobus fixed and prepared via cryosubstitution, showing the membrane-bound nuclear body with its nuclear envelope (NE) surrounding the nucleoid (N) and the more general features of the planctomycete cell plan, including the intracytoplasmic membrane (ICM) and paryphoplasm (P). (b) Transmission electron micrograph of thin section of cryosubstituted cell of Pirellula staleyi displaying compartmentalization into pirellulosome (PI) and P separated by the ICM. N is contained within the pirellulosome and thus compartmentalized and surrounded by the single ICM membrane (cited from Fuerst, 2005)

Fig. 3 Symbiosis of the ciliate Nassula ornata with algae (magnification:160 ×) (source: Wim van Egmond)

Fig. 4 Compaction of DNA into chromosome (source: Baidu photo)

Fig. 5 Packing principle of eukaryotic DNA based on “C value” of various organisms. The dotted red line with an arrow indicates evolutionary track of the median “C value”, and the dotted green line shows the major range of the “C value” of most eukaryotes. Question marks indicate uncertainity about the dates of their origins. C values of various organisms are cited from Gregory (2004)

Fig. 6 Comparison of the cell divisions between bacteria (upper figure, the bacterium Escherichia coli) and eukaryotes (lower figure) (cited from Campbell & Reece, 2008)

Fig. 7 Schematic drawing of bacterial conjugation. Conjugation diagram. 1, Donor cell produces pilus; 2, Pilus attaches to recipient cell and brings the two cells together; 3, The mobile plasmid is nicked and a single strand of DNA is then transferred to the recipient cell; 4, Both cells synthesize a complementary strand to produce a double stranded circular plasmid and also reproduce pili; both cells are now viable donors (cited from Wikipedia).

Fig. 8 The yeast cell’s life cycle. (1) Budding; (2) Conjugation; (3) Spore. (cited from Wikipedia)

Fig. 9 Life cycle of a green alga, Chlamydomonas (cited from Raven et al, 1992)

Fig. 10 Life cycle of a cyclic parthenogenetic Daphnia (after Ebert, 2005)