Polygons are 2-dimensional shapes. They are made of straight lines, and the shape is closed (all the lines connect up).
Rectopexy is a surgical procedure used to correct rectal prolapse, a condition characterized by a weakening of the muscles that hold the rectum in place. Though the exact cause of this problem is unknown, there are several conditions that may contribute to its development.
Doublesex (dsx) is a gene that is involved in the sex determination system of the fruit fly Drosophila melanogaster. The gene is expressed in both male and female flies and is subject to alternative splicing, producing the protein isoforms dsxf in females and the longer dsxm in males.