Three gene pairs located on separate autosomes determine flower c...

Question

Three gene pairs located on separate autosomes determine flower color and shape as well as plant height. The first pair exhibits incomplete dominance, where the color can be red, pink (the heterozygote), or white. The second pair leads to personate (dominant) or peloric (recessive) flower shape, while the third gene pair produces either the dominant tall trait or the recessive dwarf trait. Homozygous plants that are red, personate, and tall are crossed to those that are white, peloric, and dwarf. Determine the F₁ genotype(s) and phenotype(s). If the F₁ plants are interbred, what proportion of the offspring will exhibit the same phenotype as the F₁ plants?

Accepted Answer

Hey everyone, let's take a look at this question together. A fruit fly, which is home to Vegas for gray body normal wings and red eyes is cross with a fruit fly which is hetero zegas for the same phenotype. So what proportion of their offspring will have home as agus gray body normal wings and red eyes assume that no crossing over takes place. Let's use the L. L. B. To represent the body G. To represent the wings N. E. To represent the eyes. And so we're crossing a home as a Vegas fruit fly with a hetero ziggy's fruit fly. However, it has the same phenotype. So our homo zegas fruit fly is this and we're crossing it with that hetero saiga. So it looks like this. And since we're trying to figure out what proportion of the offspring will have the home as a Vegas for all of the dominant traits, we know that when we cross the homosexuals dominant with the hetero zegas, we have a one half proportion of homosexuals dominant to Hetero zegas. And so we're only going to be looking at the home as a guest dominant. And we're gonna use the fork method. So we know that the home azaleas dominant will also give us that one half proportion of homicide is dominant and hetero zegas. And so we're looking at this one as well, which will give us that one half or the eyes trait we have a mosaic is dominant and heterocyclic. And so we're looking at this proportion. This proportion and this proportion to figure out the offspring that have that Hamas is dominant for all three traits. So we use the product rule and we multiply one half times one half times one half because half of the offspring will have homosexuals dominant body here, Hamas is dominant for wings and Hamas is dominant or eyes. So we multiply one half times one half times one half, and we end up with 1/8 as our answer, which is answer choice. A The correct answer because the proportion of the offspring when we cross that fruit fly, that's homesickness for gray body, normal wings and red eyes with the fruit fly that it's hetero ziggy's for the same phenotype. We end up with a 1/8 proportion of their offspring being home as ideas for great body, normal wings and red eyes. I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Incomplete Dominance

Gene Interaction

Punnett Square

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