Detail of a diagram of DNA strands of two yeast strains that have been crossbred, showing where meiotic crossover has occurred. Detail shows parts of 11 of yeast's 16 chromosomes.
During meiosis, the chromosomes from male and female parents or, in this case, from the two crossbred strains of yeast (Saccharomyces cerevisiae) undergo recombination, swapping segments of homologous chromosomes. This diagram charts the crossovers among yeast's 16 chromosomes.
Image by Elizabeth A. Winzeler, Stanford University. From the cover of Science, 21 August 1998.