Which studies could be conducted using genome-wide association mapping? Biologists searching for genes governing petal color in coneflowers examine the second generation offspring of a cross between purple and white coneflowers. Scientists identify genes controlling stamen length in Arabidopsis thaliana by comparing the genomes of 6000 short-stamen plants to an equal number of long-stamen plants. Geneticists study the
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progeny of a cross between two populations of zebra finches with different body sizes to determine the locations of genes possibly involved with body size. Researchers compare the genomes of 5000 leukemia patients to the genomes of 5000 people without leukemia to identify genes associated with this type of cancer.