Information on this page has not been updated for a while! So, it may not be accurate.
| Organism | Size (bases) | Genes | Source |
| Escherichia coli (Bacterium) | 4.6 Million | 3,000 | |
| Sacchromyces cerevisiae (Yeast) | 15 Million | 6,000 | |
| Neurospora crassa (Fungus) | 39.9 Million | 10,000 (Release Apr 2003) | |
| C. elegans (Nematode) | 100 Million | 20,000 | Wormbase WS108 release |
| C. briggsae (Nematode) | 104 Million | 20,000 (Release Sept 2003) | Stein et al., PLoS Biology 2003 |
| Drosophila melanogaster (Fruit fly) | 120 Million | 13,000 | Flybase release 3.1 |
| Anapheles gambiae (Mosquito) | 280 Million | 13,600 | |
| Strongylocentrotus purpuratus (sea urchin) | 814 Million | 23,300 | Science 2006, vol. 314, 941-952 |
| Ciona intestinalis (Ascidian sea squirt) | 160 Million | 15,800 | |
| Fugu rubripes (Pufferfish) | 365 Million | 38,000 | |
| Danio rario (Zebrafish) | 1.7 Billion ? | ||
| Monodelphus domestica (opossum/metatherian/marsupial) | 3.5 billion | 20,000 | Nature 2007, vol. 447, 167-177 |
| Mouse | 3 billion | 30,000 | |
| Gallus gallus (Chicken) | 1.2 Billion | Nature 2004, vol. 432, 679-680 | |
| Xenopus laevis (Frog) | 3 Billion | ||
| Human | 3 Billion | 23,000 | |
| Human: largest chromosome (chr 1) | 250 Million | ||
| Human: smallest chromosome (Y) | 50 Million | ||
| Daphnia pulex (crustacean/water-flea) | 200 Million | 31,000 | Science 2011, vol. 331, pp. 555-561 |
| Arabidopsis thaliana (flower) | 100 Million | ||
| Rice cereal (subspecies: indica) | 465 Million |