In wheat, awnlessness (A) dominates over the awnness (a), and the red coloration of the spike (B)

In wheat, awnlessness (A) dominates over the awnness (a), and the red coloration of the spike (B) over white (i). Plants of the boneless red-ear cultivar, when crossed with wheat of the awned white-ear cultivar, yielded: * 1/4 awnless red-ears, * 1/4 awnless white-ears, * 1/4 awned red-ears, * 1/4 awnless white-ears.

According to the notation introduced in the condition of the problem, we will write the white-spiked wheat as aabb, because homozygosity is an indispensable condition for the phenotypic realization of traits related to recessive. Such wheat produces germ cells of one type – ab. She can pass on to the offspring only the genes of spinous and white-haired.

Since there are plants in the offspring that demonstrate recessive traits, and, therefore, have the aavv genotype, it should be concluded that both traits are heterozygous for the hardy red-ear wheat.

Let’s write it down as AaBb, the germ cells produced by it – ab, AB, Ab, aB.

This crossing by type can be classified as analyzing.

The offspring from crossing the described plants will have the following appearance:

bristle wheat with white ears (aabb) – 25%;

awnless wheat with a red ear (AaBb) – 25%;

awnless wheat with white ears (Aabb) – 25%;

bristle wheat with red ears (aaBb) – 25%.

The resulting percentage corresponds to the proportions given in the condition.

Answer: white-spiked awnless – aabb, red-spiked awnless – AaBb.