ABSTRACT
From our study of meiosis we have gained a clear understanding of the behavior of chromosomes, and the DNA molecules that they contain, during sexual reproduction. In particular we have learned that formation of bivalents between homologous chromosomes is the key step that leads to genetic variability among the gametes resulting from meiosis. New allele combinations are generated by recombination within bivalents and by random segregation of homologous chromosomes when the bivalents break down.
