Concept explainers
A dark-red strain and a white strain of wheat are crossed and produce an intermediate, medium-redF1. When the F1 plants are interbred, an F2 generation is produced in a ratio of 1 dark-red: 4 medium-dark-red: 6 medium-red: 4 light-red: 1 white. Further crosses reveal that the dark-red and white F2 plants are true breeding.
(a) Based on the ratios in the F2 population, how many genes are involved in the production of color?
(b) How many additive alleles are needed to produce each possible phenotype?
(c) Assign symbols to these alleles and list possible genotypes that give rise to the medium-red and light-red
(d) Predict the outcome of the F1 and F2 generations in a cross between a true-breeding medium-red plant and a white plant.
Want to see the full answer?
Check out a sample textbook solutionChapter 21 Solutions
ESSENTIALS OF GENETICS MCC BUNDLE >BI<
- Two true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high. What would be the size and genotype of the F1 from a cross between a true-breeding 11 cm plant and a true-breeding 47 cm plant? Please answer the following problem & EXPLAIN your answer showing ALL WORKING.arrow_forwardTwo true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high. The F1 from (b) is then crossed to give an F2. What proportion would you expect in the F2 of each extreme phenotype?arrow_forwardTwo true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high.So What would be the size and genotype of the F1 from a cross between a true-breeding 11 cm plant and a true-breeding 47 cm plant?arrow_forward
- A dark-red strain and a white strain of wheat are crossed andproduce an intermediate, medium-red F1. When the F1 plants areinterbred, an F2 generation is produced in a ratio of 1 dark-red:4 medium-dark-red: 6 medium-red: 4 light-red: 1 white. Furthercrosses reveal that the dark-red and white F2 plants are truebreeding. How many additive alleles are needed to produce each possiblephenotype?arrow_forwardA dark-red strain and a white strain of wheat are crossed and produce an intermediate, medium-red F1. When the F1 plants are interbred, an F2 generation is produced in a ratio of 1 dark-red: 4 medium-dark-red: 6 medium-red: 4 light-red: 1 white. Further crosses reveal that the dark-red and white F2 plants are true breeding. Predict the outcome of the F1 and F2 generations in a cross between a true-breeding medium-red plant and a white plant.arrow_forwardAssume that three loci, each with two alleles (A and a, B and b, C and c), determine the difference in height between two homozygous strains of a plant. These genes are additive and equal in their effects on plant height. One strain (aa bb cc) is 10 cm in height. The other strain (AA BB CC) is 22 cm in height. The two strains are crossed, and the resulting F1 are interbred to produce F2 progeny. Give the phenotypes and the expected proportions of the F2 progeny.arrow_forward
- Assume that the length of a type of cucumber at maturity is controlled by two genes (A and B), each of which has two alleles. The A and B alleles each add 3 inches of cucumber growth, while the a and b alleles add only 1 inches. If a plant with genotype AABb is crossed to a plant with genotype AaBb, what ratio of lengths are expected in the progeny? 1/8-12”, 3/8-10”, 3/8-8”, 1/8-6” 1/2-8”, 3/8-6”, 1/8 4” 1/2-10”, 3/8-8”, 1/8 6” 1/2-12”, 3/8-10”, 1/8 8” 1/8-10”, 3/8-8”, 3/8-6”, 1/8-4”arrow_forwardTwo true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high. a) How many i) genes and ii) how many alleles are involved in determining height in this plant? b) What is the contribution of each dominant allele to the phenotype in cm? c) What would be the size and genotype of the F1 from a cross between a true-breeding 11 cm plant and a true-breeding 47 cm plant? d) The F1 from (b) is then crossed to give an F2. What proportion would you expect in the F2 of each extreme phenotype?e) In a cross between a 29cm plant and a 20cm plant what would be the genotypes giving the smallest number of different phenotypes? specify the phenotypes observed.arrow_forwardTwo true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high. a) How many i) genes and ii) how many alleles are involved in determining height in this plant? b) What is the contribution of each dominant allele to the phenotype in cm? c) What would be the size and genotype of the F1 from a cross between a true-breeding 11 cm plant and a true-breeding 47 cm plant? d) The F1 from (b) is then crossed to give an F2. What proportion would you expect in the F2 of each extreme phenotype? e) In a cross between a 29cm plant and a 20cm plant what would be the genotypes giving the smallest number of different phenotypes? specify the phenotypes observed. Please answer the following problem & EXPLAIN your answer…arrow_forward
- Two true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant F1 hybrids were then crossed to generate the F2 . In the F2 there were a total of 13,923 plants with a continuous variation in heights between the two extremes and with only 3 plants as large as 47 cm high and 5 plants of 11 cm high. e) In a cross between a 29cm plant and a 20cm plant what would be the genotypes giving the smallest number of different phenotypes? specify the phenotypes observed. Please answer the following problem & EXPLAIN your answer showing ALL WORKING.arrow_forwardIn peas, purple flowers are dominant to white. If a purple-flowered, heterozygous plant were crossed with a white-flowered plant, what is the expected ratio of genotypes and phenotypes among the F1F1offspring? If two of the purple-flowered F1F1 offspring were randomly selected and crossed, what is the expected ratio of genotypes and phenotypes among the F2F2 offspring?arrow_forwardIn an intra-species cross performed in mustard plants of two different species (Brassica juncea and Brassica oleracea), a tall plant (TT) was crossed with a dwarf (tt) variety in each of the two species. The members of the F1 generation were crossed to produce the F2 generation. Of the F2 plants, Brassica juncea had 60 tall and 20 dwarf plants, while Brassica oleracea had 100 tall and 20 dwarf plants. Use chi-square analysis to analyze these results.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education