Summary: Dr. Meyer explains the value of studying model organisms and introduces the nematode C. elegans Affectionally known as "the worm," it has two sexes: male, which possesses a single X chromosome, and hermaphrodite, which possesses two X chromosomes. Dr. Meyer explains that sex determination is controlled by the xol-1 gene. Xol-1 gene expression is regulated by sex-determining factors produced by the X chromosome.
