Waxy endosperm (T), shrunken endosperm (B), and yellow seedling (D) are encoded by three recessive genes in corn that are linked on chromosome 5. A corn plant homozygous for all three recessive alleles is crossed with a plant homozygous for all the dominant alleles. The resulting F1 are then crossed with a plant homozygous for the recessive alleles in a three‑point testcross. The progeny of the testcross are listed in the table in a random order. t b D 87 T B d 94 T B D 3479 t b d 3478 T b D 1515 t B d 1531 t B D 292 T b d 280 Total 10756   Place each gene in the correct order on the chromosome. Locus 1 Locus 2 Locus 3   [ Select ] D T B [ Select ] T D B [ Select ] B D T