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Colored aleurone in the kernels of com is due to the dominant allele R. The recessive allele r, when homozygous, produces colorless aleurone. The plant color (not the kernel color) is controlled by another gene with two alleles, Y and y. The dominant Y allele results in green color, whereas the homozygous presence of the recessive y allele causes the plant to appear yellow. In a testcross between a plant of unknown genotype and
Explain how these results were obtained by determining the exact genotype and phenotype of the unknown plant, including the precise arrangement of the alleles on the homologs.
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- In sweet pea plant, an allele for purple flowers (P) is dominant when paired with a recessive allele for red flowers (p). An allele for long pollen grains (L) is dominant when paired with a recessive allele for round pollen grain (l). Bateson and Punnett crossed a plant having purple flowers/long pollen grains with one having white/flowers/round pollen grains. All F1 offspring had purple flowers and long pollen grains. Among the F2 generation, the researchers observed the following phenotypes: 296 purple flowers/long pollen grains 19 purple flowers/round pollen grains 27 red flowers/long pollen grains 85 red flowers/round pollen grains What is the best explanation for these results?arrow_forwardFigure 8.10 In pea plants, purple flowers (P) are dominant to white (p), and yellow peas (Y) are dominant to green (y). What are the possible genotypes and phenotypes for a cross between PpYY and ppYy pea plants? How many squares would you need to complete a Punnett square analysis of this cross?arrow_forwardHemophilia and color blindness are both recessive conditions caused by genes on the X chromosome. To calculate the recombination frequency between the two genes, you draw a large number of pedigrees that include grandfathers with both hemophilia and color blindness, their daughters (who presumably have one chromosome with two normal alleles and one chromosome with two mutant alleles), and the daughters sons. Analyzing all the pedigrees together shows that 25 grandsons have both color blindness and hemophilia, 24 have neither of the traits, 1 has color blindness only, and 1 has hemophilia only. How many centimorgans (map units) separate the hemophilia locus from the locus for color blindness?arrow_forward
- The genes for tall vine D and yellow seed G, are dominant over their respective alleles for dwarf d and green g. What phenotypes are expected from each of the following crosses? Include phenotypic and genotypic ratio. Use Punnet square to show the ff. Crosses. a. Heterozygous tall, homozygous yellow X Homozygous Tall, heterozygous yellow. b. Homozygous Dwarf, heterozygous yellow X Heterozygous tall, homozygous greenarrow_forwardIn corn plants, a dominant allele (K) allows kernel colour and a recessive allele (k) inhibits kernel colour when homozygous. On a different chromosome, the dominant gene P causes purple kernel colour and the homozygous recessive genotype causes red kernel colour.A true breeding white corn plant was crossed with a purple corn plant, yielding 50% red corn plants and 50% purple corn plants.What are the genotypes of the parental corn plants? Select one: a. KKPp kkpp b. KkPP kkPP c. kkPp KkPp d. KKPP kkPparrow_forwardIn corn, a colored aleurone is due to the presence of an R allele; r/r is colorless. Another gene controls the color of the plant, with g/g being yellow and G_being green. A plant of unknown genotype is test-crossed, and the following progeny plants were obtained. Colored green 89 Colored yellow 13 Colorless green 9 Colorless yellow 92 What was the phenotype and genotype of the plant used for the test cross? A. Colorless green - rG/rg B. Colorless yellow - rg/rg C. Colored yellow - Rg/rg D. Colored green - RG/rgarrow_forward
- Tomato Plants In tomato plants, round fruit (R) is dominant to oval fruit (r). Pure breeding plants with red and round fruit (FFRR) were crossed to pure breeding plants with yellow and oval fruit (ffrr). The red and round F1 progeny were then testcrossed to plants that were homozygous recessive for both genes (ffrr) with the following results: Phenotypes Number of Offspring Red and round 2 255 Red and oval 290 Yellow and round 310 Yellow and oval 2 145 Complete a Punnett square to determine the expected testcross progeny on the basis of Mendel’s Law of Independent Assortment. Record the phenotypes and the phenotype ratio in lowest terms.arrow_forwardTomato Plants In tomato plants, round fruit (R) is dominant to oval fruit (r). Pure breeding plants with red and round fruit (FFRR) were crossed to pure breeding plants with yellow and oval fruit (ffrr). The red and round F1 progeny were then testcrossed to plants that were homozygous recessive for both genes (ffrr) with the following results: Phenotypes Number of Offspring Red and round 2 255 Red and oval 290 Yellow and round 310 Yellow and oval 2 145 Part A: Record the phenotypes and the phenotype ratio in lowest terms. Part B: Convert the expected phenotypic ratio from Part A into the expected probability for each of the four phenotypes and record them in the table below. Calculate the probability for each of the four phenotypes observed in the cross from the data presented at the beginning of the question by dividing the number of progeny in each class by the total number of progeny and record these in the table below. (Probability = Number of Progeny in Phenotype…arrow_forwardTomato Plants In tomato plants, round fruit (R) is dominant to oval fruit (r). Pure breeding plants with red and round fruit (FFRR) were crossed to pure breeding plants with yellow and oval fruit (ffrr). The red and round F1 progeny were then testcrossed to plants that were homozygous recessive for both genes (ffrr) with the following results: Phenotypes Number of Offspring Red and round 2 255 Red and oval 290 Yellow and round 310 Yellow and oval 2 145 Part A: Record the phenotypes and the phenotype ratio in lowest terms. Part B: Convert the expected phenotypic ratio from Part A into the expected probability for each of the four phenotypes and record them in the table below. Calculate the probability for each of the four phenotypes observed in the cross from the data presented at the beginning of the question by dividing the number of progeny in each class by the total number of progeny and record these in the table below. Probability = Number of Progeny in Phenotype…arrow_forward
- Kernel color in wheat is controlled by 2 pairs of genes (AABB). Determine the color of each offspring with the following genotypes: (Note: 4 alleles – red; 3 – medium red; 2 – intermediate red; 1 – light red; 0 – white). CAPITAL letters only and with spaces when applicable. AABb - AaBb - AABB - aaBb - aabb -arrow_forwardThe shape of a pumpkin is determined by the action of two genes A and B. The recessive forms of these two alleles produces a flattened-shaped fruit, whereas the dominant forms of these two alleles produce the typical pumpkin with ridges. When both alleles are heterozygous a disc-shaped pumpkin is produced. If the genotype of the pumpkin plant is homozygous dominant at one allele and heterozygous at the other, the pumpkin will be ball-shaped. If the pumpkin plant is homozygous recessive at one allele and heterozygous at the other allele it produces an oblong-shaped fruit. Plants with genotypes other than the ones listed in this question do not produce pumpkins. Do the following cross: two pumpkin plants capable of making disc-shaped pumpkins are crossed with each other. Based on this cross, answer the following: (Show your work below.) How many of the progeny will make ball-shaped pumpkins?__________________________________________ How many of the progeny will make disc-shaped…arrow_forwardTallness (T) in a certain plant is dominant to short (t), while red (R) flower color is dominant to yellow (r). The heterozygous condition results in orange (Rr) flower color. A short plant with red flowers, is crossed with a plant homozygous for tallness and yellow flowers. What would be the genotype and phenotype of the F1 individuals? ttRr—short and orange ttrr—short and yellow TtRr—tall and red Ttrr—tall and yellow TtRr—tall and orangearrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College