JACOPIN / BSIP / SCIENCE PHOTO LIBRARY JACOPIN / BSIP / SCIENCE PHOTO LIBRARY
Illustration of the various trisomies highlighted on a genetic map. Each person has 22 pairs of chromosomes and two unique sex chromosomes. Seen here, the X and Y of a little girl. Trisomy concerns chromosomes 13, 18 and 21, who have three identical chromosomes instead of a pair.
Model release not required. Property release not required.