Satellite biological experiments--major results and problems.

The data on the results of biological experiments carried out on Vostok 5 and Vostok 6 are presented. Space flight factors are shown to cause in hereditary structures of some biological objects (seeds of higher plants, lysogenic bacteria, Tradescantia microspores, etc.) distortions of a small but statistically significant value. Changes in physiological functions of certain objects (seeds of higher plants, etc.) have been also detected. These data are in good agreement with the results of flight experiments carried out in 1960-1962. Prospects of research of the biological effect of cosmic radiation and weightlessness are considered with respect to flight experiments.