What is the phenotypic ratio of a cross between a pink and a white snapdragon?
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If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. Problem 10: Disappearance of parental phenotypes in the F1 generationA genetic cross of inbred snapdragons with red flowers with inbred snapdragons with white flowers resulted in F1-hybrid offspring that all had pink flowers. When the F1 plants were self-pollinated, the resulting F2-generation plants had a phenotypic ratio of 1 red: 2 pink: 1 white. The most likely explanation is:TutorialIncomplete dominanceThe F1-hybrid plants have a different phenotype (pink flowers) than either of the true-breeding parents. This is an example of incomplete dominance. When the F1-hybrid plants are self-fertilized, both parental phenotypes (red flowered plants and white flowered plants) reappear in the F2 generation.The Biology Project http://www.biology.arizona.edu Snapdragon flowers (pictured) show incomplete dominance in the color of their petals. The petals can be red, CR CR white, CW CW, or pink, CR CW. Two pink flowers are crossed. What is the probability, in percent, that their offspring will also have pink flowers? Let’s start by annotating our diagram with the information given to us in the question. We are told that the genotype of red snapdragons is CR CR. The C means color and the R means red. Remember, the set of alleles an organism possesses for a characteristic is their genotype. We are also told that the genotype of white snapdragon flowers is CW CW, where this time the superscript W means white. Finally, we know that the genotype of pink snapdragon flowers is CR CW. The phenotype is the observable trait that is produced by the genotype. In these cases, the phenotype of each individual plant is its flower color, red, white, or pink. The question states that the inheritance of flower color in snapdragons shows incomplete dominance. Allele show in complete dominance when an intermediate phenotype is created in an organism that is heterozygous for a particular trait, which means that they have one of each allele. In this example, the intermediate phenotype is the pink flower color, as it is a blend between the white and red flowers and has a heterozygous genotype. Let’s draw a Punnett square to work out the percentage of offspring likely to be pink when these two parent plants with pink flowers reproduce. Punnett squares like this one are used to visually represent how alleles are inherited and predict the genotypes and phenotypes of the offspring produced by crossing parents with known genotypes. We know that pink snapdragons have the genotype CR CW. We put the alleles that will be present in one parent’s gametes in the top row and we put the alleles that will be present in the other parent’s gametes in the left column. Now we need to fill in the blank cells with the potential offspring genotypes that are able to be produced from a cross between these two pink parents. We do this by taking the alleles in the gametes from each row and column head, for example, the CR allele from this parent and the CR allele from this other parent. Let’s do this for the rest of the cells. We can see in the Punnett square that one out of four of the offspring has the genotype CR CR and so has a red-flowered phenotype. We can also see that one out of four of the offspring has the genotype CW CW and so a white-flowered phenotype. Finally, two out of the four offspring produced in this cross have the heterozygous genotype CR CW and so have a pink-flowered phenotype. The question asks us to determine the probability in percent that the offspring produced by this cross will have pink flowers. So let’s do this by converting this value into a percentage by multiplying it by 100 percent. Therefore, the probability that the offspring produced by two pink snapdragons will also be pink is 50 percent. What is the phenotypic ratio of the cross snapdragon flowers?In snapdragon (Antirrhinum anus) the cross between a red-flowered plant (RR) and a white-flowered plant (rr) results in all pink flowered (Rr) plants in the F1 generation. A self-cross between two F1 plants results in red, pink and white flowers in the ratio of 1:2:1.
What is the phenotype of pink snapdragon?Finally, we know that the genotype of pink snapdragon flowers is CR CW. The phenotype is the observable trait that is produced by the genotype. In these cases, the phenotype of each individual plant is its flower color, red, white, or pink.
When pink and white flowered plants of snapdragon are crossed?This is seen in the case of Antirrhinum (snapdragon), a cross between red coloured snapdragon flower and white coloured flower plants results in the production of a pink coloured flower plant in the F1 generation, and neither of the parental phenotypes get masked.
When a pink flower and white flower are crossed what will be the genotypic ratio?So, the correct option is 'Pink and white in 1 : 1 ratio'.
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