The Australian grass tree, from the genus Xanthorrhoea in the lily family, grows to a height of about 4.5 m, bears long narrow leaves in a tuft at the top of the trunk, and produces yellow or white flowers in a spike above the leaves. A yellow-flowered tree was self-crossed. The seeds were collected and planted. The resulting progeny were 31 yellow-flowered trees and 8 white-flowered trees.

Question

The Australian grass tree, from the genus Xanthorrhoea in the lily family, grows to a height of about 4.5 m, bears long narrow leaves in a tuft at the top of the trunk, and produces yellow or white flowers in a spike above the leaves. A yellow-flowered tree was self-crossed. The seeds were collected and planted. The resulting progeny were 31 yellow-flowered trees and 8 white-flowered trees.

What is the dominant phenotype?

Yellow

Whites

Answer 1

The dominant phenotype in this case is the yellow-flowered trees. To determine this, you would need to analyze the ratio of yellow-flowered trees to white-flowered trees in the offspring.

In this scenario, there were a total of 39 trees produced from the self-crossing of the yellow-flowered tree. Among these offspring, 31 trees had yellow flowers while 8 trees had white flowers.

To determine the dominant phenotype, we compare the number of trees with the yellow phenotype to the number of trees with the white phenotype. Since there are more yellow-flowered trees (31) than white-flowered trees (8), we can conclude that yellow is the dominant phenotype in this case.