Two pure-breeding wheat strains, one producing dark red kernels a...

Question

Two pure-breeding wheat strains, one producing dark red kernels and the other producing white kernels, are crossed to produce F₁ with pink kernel color. When an F₁ plant is self-fertilized and its seed collected and planted, the resulting F₂ consist of 160 plants with kernel colors as shown in the following table.

Kernel Color Number
White   9
Dark red 12
Red 39
Light pink 41
Pink 59

Using clearly defined allele symbols of your choice, give genotypes for the parental strains and the F₁. Describe the genotypes that produce the different phenotypes in the F₂.

Accepted Answer

Hello everyone and welcome to today's video. So in P plans, tallness or capital T is dominant over shortness or lower case D and round shape, CD or capitalized R is dominant over wrinkled seed shape or lowercase R. So we had that two pure reading piece trains tall and brown seeds with a fully homozygous dominant genotype and short and wrinkled seed with a fully homozygous recessive genotype are cross to produce the F one generation with tall and brown seeds which are fully heterozygous four T and R. So when the F one generation so fertilizes the resulting F two generation has 300 plants with different chiefs and plant heights. So what is the probability of obtaining a plant having brown seeds in the F two generation? And so we are given a table with the genotypes of the F two generations and the number of individuals. Well, in order to solve this problem, we need to understand that in order to determine which seeds have or which plants have brown seeds, we need to look at the genotype that's going to give us round seeds shape and this is going to be the capitalized R. So any of these genotypes that have a capitalized R is going to result in round seeds, which in this case is going to be the first one, the second one and the third one, because all of these are going to contain a capitalized R or a dominant A which is going to yield this round C G which is the dominant penalty. So all we need to do is to add up all of the individuals that have the dominant R A divided by the total number of individuals in the population. And we will obtain the probability. So let's write that down so that total number of R individuals or individuals with the R dominant divided by the total number of individuals. So the first genotype is going to be the homo, the fully homozygote for T N R which is going to be individuals. Then we add this by the second one, which is going to be the fully heterozygote on R which is going to be individuals. And then we add this by the third one which is going to be homozygosis for T homozygote dominant for R which is 47. So all of these contain these dominant or a and then we divide it by 300 individuals, which is what the total number of offspring in the F two generation is stated to be. And this is going to yield 0. which can also be stated to be 95%. So this is going to be the probability of obtaining an individual with ground seeds in the F two regeneration, which is represented by answer choice, the 95%. I really hope this helped and I hope to see you on the next video.

Key Concepts

Mendelian Inheritance

Genotype and Phenotype

Punnett Square

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