ABSTRACT
Experiments to study the effect of weightlessness on the emergence and development of cell organelles and genetic structures were carried out during 18.5 days aboard the biological satellite Cosmos-936. The experiments were conducted on the fruit fly Drosophila melanogaster Orgeon-R. Their purpose was to investigate possible chromosomal aberrations and gene mutations in the sex chromosomes of males and females. The investigations showed that the frequency of mutations in the progeny of specimens exposed to weightlessness did not differ from the controls. The experiments with higher plants were performed on the seedlings of Crepis capillaris and Zea mays grown from seeds aboard the biosatellite. The cytological examination of Crepis capillaris chromosomes demonstrated that there were no structural chromosome changes in the experimental and control variants. Maize seedlings grown in weightlessness and examined later in the laboratory showed that cells of the root meristem cultivated in weightlessness were much larger than the controls. Mitochondria of seedlings exposed to weightlessness were swollen and had a low content of membranous material.
