In lentils, seed color is controlled by two genes. When homozygous tan and grey lentils are crossed, all the F1 progeny are brown lentils. When the dihybrid F1 progeny are crossed, the phenotypic ratio of the F2 is 9 brown : 3 tan : 3 grey : 1 green. If lentil seed color were instead controlled by one gene (A) with two incompletely dominant alleles, and homozygous tan and grey lentils were crossed as described above, what results would be expected?

If the F1 is self crossed (Aa X Aa), the resulting offspring will be:

1: AA (tan) 2: Aa (brown) 1: aa (grey).

Explanation:

If lentil seed color were instead controlled by one gene (A) with two incompletely dominant alleles, the heterozygous individual (Aa) shows a phenotype different than the homozygous AA or aa phenotypes.

In this case, homozygous tan (AA) is crossed with homozygous grey (aa) producing the Aa brown F1.

If the F1 is self crossed (Aa X Aa), the resulting offspring will be:

1: AA (tan)

2: Aa (brown)

1: aa (grey).

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