Epistatic gene interaction results in a modification of ...

Question

Epistatic gene interaction results in a modification of the F₂ dihybrid ratio.

Give two examples of modified F₂ ratios produced by epistatic gene interactions and describe how gene interaction results in the ratios.

Accepted Answer

Everyone. Welcome back. This is our next problem. It says what is the fanatic ratio of a dominant episodic interaction? Dominic dominant episodic interaction, a dominant alil of our episodic gene will mask the expression of the hyper static gene. So in this case, we know that when we have a di hybrid cross, we know we have two genes because we're talking about episode Asus. So I die hybrid cross without episode, Asus would normally give us a fanatic ratio of 9-3, 2, 3, 2, 1 Where nine is both dominant traits being expressed three being one dominant, one recessive, The other three being one dominant, one recessive switched around and one being both recessive traits. Well, in a dominant episodic interaction, every time there's a dominant allele of the aesthetic gene, you're going to express that dominant phenotype above everything. So this nine and this three will be combined because these are both cases where we have a dominant gene from our app static dream. So this nine and three will add together to make 12 expressing the dominant phenotype as determined by the episodic dream. So it masks whatever is happening with the hyper static gene, this other three will reflect a recessive episodic gene. So it isn't masking and it will show the dominant trait from the hyper static gene. And the one here will show both recessive traits from both genes. So our fanatic ratio then for a dominant aesthetic interaction will reflect 12-3-1. So that's gonna be our choice. A 12-3-1. Let's look through other answer choices to see why they are not correct. Choice B is 1-2-1. Well, this would be the ratio if you have only a mono hybrid cross, just a single gene, which is not the case, whenever there's episode Asus, you have two genes. So choice B cannot be correct. Choice E is 9-3-3-1. But as we discuss, that's our ratio of a di hybrid cross with no episode Asus. So that's why that one is not correct. So we eliminate choice C And then choice D 9-3-4 is the ratio get with recessive epa stasis. And that's because looking back at my 9 to 3 to 3 to 1 in recessive episode, this episode, Asus, the effect of the hyper static gene is masked whenever the epa static gene is expressed in the homos, I guess recessive condition. In that case, we'd add together the one which is both recessive with a three, which would reflect the recessive episodic gene Making that final # four expressing both recessive traits, The initial nine and 3 would be unaffected because in those cases, the episodic gene is present either in the dominant homos, august dominant or the hetero sickos form. And you need both alleles of the episodic gene to be recessive to have its masking effect. So the nine and the three are unaffected and you end up with a phenotype ratio of 9 to 3 to four with recessive episodic interaction. So that's why choice D isn't correct. So again, what is the fanatic ratio of a dominant aesthetic interaction? Choice? A 12-3-1? See you in the next video?

Epistatic gene interaction results in a modification of the F₂ dihybrid ratio.

Give two examples of modified F₂ ratios produced by epistatic gene interactions and describe how gene interaction results in the ratios.

Key Concepts

Epistasis

Dihybrid Cross

Modified F₂ Ratios

Watch next

Epistatic gene interaction results in a modification of the F₂ dihybrid ratio.Give two examples of modified F₂ ratios produced by epistatic gene interactions and describe how gene interaction results in the ratios.

Key Concepts

Epistasis

Dihybrid Cross

Modified F₂ Ratios

Watch next

Epistatic gene interaction results in a modification of the F₂ dihybrid ratio.

Give two examples of modified F₂ ratios produced by epistatic gene interactions and describe how gene interaction results in the ratios.