Abstract: | Abstract— The dose dependence of chromosomal aberration frequencies induced by UV light in G1Xenopus cells has been examined. Total aberration frequencies did not exceed control levels until a dose of approximately 7.5 Jm-2 was administered. Chromatid type aberrations were prevalent throughout the dose range 7.5–25.0 Jm-2. Chromosome type aberration frequencies were comparatively low but exceeded control levels throughout the range 10.0–25.0 Jm-2, Results of supporting experiments suggested that most of the chromosome type aberrations observed were in the second mitosis following exposures and were derived from aberrations which normally appear as chromatid types at the first mitosis following exposures. |