In people with chronic myelogenous leukemia, the chromosomes in the blood cells swap sections with each other. A section of chromosome 9 switches places with a section of chromosome 22, creating an extra-short chromosome 22 and an extra-long chromosome 9.
Discovered on September 23, 1846, by John Couch Adams. Neptune was the first planet found by mathematical prediction rather than by observation. Unexpected changes in the orbit of Uranus led astronomers to deduce that its orbit was subject to gravitational perturbation by an unknown planet.
1 NASA's Voyager 2 probe captured this image of Neptune five days before its historic flyby of the planet on Aug. 25, 1989. 2  Members of the Voyager science team look at new images of Neptune's moon Triton as information from NASA's Voyager 2 probe comes down to Earth in August 1989.