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Three pairs of genes with two alleles each (
a. What are the expected heights of plants with each of the homozygous genotypes
b. What height is expected in the
c. What is the expected height of a plant with the genotype
d. Identify all possible genotypes for plants with an expected height of
e. Identify the number of different genotypes that are possible with these three genes.
f. Identify the number of different
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Chapter 21 Solutions
Genetic Analysis: An Integrated Approach (2nd Edition)
- In garden pea plants, tall stem height (T) is dominant over short stem height (t), and green pod colour (G) is dominant over yellow pod colour (g). Some Genotypes of Pea Plants TTGG TTGg TTgg TtGG TtGg Ttgg ttGG ttGg ttgg Identify the correct genotypes listed above for the pea plant phenotypes described below. Phenotype Number Pure breeding tall, green pod pea plant Answer Pea plant used for a test cross Answer Heterozygous tall and green pod pea plant Answer Yellow pod heterozygous tall pea plant Answerarrow_forwardSeed weight in a particular plant species is determined by pairs of alleles attwo loci (a+ a− and b+ b−) that are additive and equal in their effects. Plantswith genotype a− a− b− b− have seeds that average 1 g in weight, whereasplants with genotype a+ a+ b+ b+ have seeds that average 3.4 g in weight. Aplant with genotype a− a− b− b− is crossed with a plant of genotype a+ a+ b+b+.a. What is the predicted weight of seeds from the F1 progeny of this cross?b. If the F1 plants are intercrossed, what are the expected seed weights andproportions of the F2 plants?arrow_forwardIn corn plants, a dominant allele (1) inhibits the expression of kernel color, while the recessive allele (1) promotes the expression of kernel color when homozygous. Another dominant allele, (P), causes purple kernel color, while the homozygous recessive genotype (pp) causes red kernels. Assuming that these alleles assort independently, predict the phenotypic ratio of the offspring if two plants dihybrid for these characteristics are crossed.arrow_forward
- Compare the sample variances of P1 and P2. Account for any differences. Similarly, compare the sample variances of the F1 and F2 generations, and account for any differences. Give the possible causes of variation in each generation.arrow_forwarda. What type of trait is this? How many genes and alleles are involved? Explain your answer. b. What are the genotypes of the 90 and 100 cm plants respectively in the parental generation? c. What is the possible genotype, or genotypes, of the 95 cm class in the F2? c. What is the possible genotype, or genotypes, of the 95 cm class in the F2?arrow_forwardSunflowers with flowers 10 cm in diameter are crossed with a plant that has 20-cm flowers. The F1 plants have flowers 15 cm in diameter. In the F2 generation, 4 flowers are 10 cm in diameter and 4 are 20 cm in diameter. Between these are 5 phenotypic classes with diameters intermediate to those at the extremes. a. Assuming that the alleles that contribute to flower diameter act additively, how many genes control flower size in this strain of sunflowers? b. How much does each additive allele contribute to flower diameter? c. What size flower makes up the largest phenotypic class?arrow_forward
- Solve this problem using a punnett square. Problem: The trait for stem length in plant Z is controlled by 3 pairs of genes. Assume that stem length in a plant is controlled by three gene pairs and that each additive allele contributes 15 cm to a base stem length of 10 cm. a. What is the height of an AaBbCC plant? b. Predict the phenotypic ratio of Fl plants in a cross between AaBbcc and AaBBcc. c. Base your answer in "letter b". If the genotypes in Fl plants that gives rise to 70cm and 25cm stem length are crossed, list all the genotypes that give rise to plants (F2) that have a stem length of 55 cm and 40 cm, respectively.arrow_forwardTwo strains of corn are 1 m (100 cm) and 3.4 m (340 cm) tall. Assume the difference arises from alleles at four genes, each with two alleles, with one allele of each gene contributing additively to height. The 3.4-m plant's genotype is AABBCCDD and the 1-m plant is aabbccdd. Part 1 How many centimeters of height does each allele that is represented by a capital letter contribute? 1.7 cm 30 cm 42.5 cm 60 cm 120 cm Part 2 What would be the shortest plants produced from the following cross? AaBBccDd× AabbccDd 100 cm 120 cm 130 cm 160 cm 175 cmarrow_forwardA pea plant believed to be heterozygous was selfed and produced pods with the followingphenotypes: 26 constricted yellow73 constricted green83 inflated yellow251 inflated green a. Using the letters A and B, assign alleles to the different traits.b. Determine whether the ratio of pea pods support the hypothesis that the plant isheterozygous.arrow_forward
- Stem length in plants is controlled by two CODOMINANT alleles of one autosomal - one allele, B, adds 2 cm to the length of the plant, and another allele, b reduces length by 0.5 cm. The base length of the plant's stem is 10 cm. A plant breeder wants to breed plants that are exactly 14.5 cm in stem length. He starts with crossing two heterozygotes, Bb x Bb. gene Assuming that you can ONLY breed plants of the same stem length, what cross(es) would the breeder have to set up in order to achieve this? Let's (i) (ii) that stem length segregates independently from flower color (also a say monogenic, autosomal, biallelic trait). If you crossed a homozygote from (i) i.e. a bb and homozygote red flowers with a plant that is homozygote BB and homozygote white flowers, intercross the F1, and observe the following numbers of progeny in the F2 generation: (iii) Height Flower Color Observed Number 14 cm Red 2 14 cm 14 cm Pink White 11.5 cm Red 7 11.5 cm Pink 13 11.5 cm White 6. 9 cm Red 9 cm Pink 6.…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_forwarda. 1 dominant allele will contribute 120/10 = 12 cm to the base height of the plant.b. The height of the parent plant 1 Genotype of the parent plant 1 – D1D1D2D2D3D3d4d4d5d5 The height of the parent plant 2 Genotype of the parent plant 2 – d1d1d2d2d3d3D4D4D5D5Contributing alleles – D4D4D5D5. The height of the plant without any contributing alleles would be 80 cm. The plant with genotype d1d1d2d2d3d3D4D4D5D5 has 4 contributing allele each of which contributes 12 cm to the base. Hence, the height of the plant with genotype d1d1d2d2d3d3D4D4D5D5 would be 80 + 12 + 12 + 12 + 12 = 128 cm. c. Parents – D1D1D2D2D3D3d4d4d5d5 × d1d1d2d2d3d3D4D4D5D5 Gametes – D1D2D3d4d5 × d1d2d3D4D5 F1 generation – D1d1D2d2D3d3D4d4D5d5 The height of the plants of F1 generation = 80 + 12 + 12 + 12 + 12 + 12 = 140 cm Hence, Genotype of the F1 = D1d1D2d2D3d3D4d4D5d5 Phenotype of…arrow_forward
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning