Concept explainers
Two pure-breeding strains of summer squash producing yellow fruit,
a. Examine the results of each cross and predict how many genes are responsible for fruit-color determination in summer squash. Justify your answer. b. Using clearly defined symbols of your choice, give the genotypes of parental,
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- What are the expected phenotypic ratios from the following cross:Tt Rr yy Aa × Tt rr YY Aa, where T = tall, t = dwarf, R = round,r = wrinkled, Y = yellow, y = green, A = axial, a = terminal; T, R,Y, and A are dominant alleles. Note: Consider using the multiplication method in answering this problemarrow_forwardFor the cross: PpAa x PpAa P = purple flowers (Dominant) p = white flowers A = axial flowers (Dominant) a = terminal flowers a. What are the possible gamete classes that can form from these parents? b. What are the expected offspring genotype classes and ratios/proportions/fractions which will result from the cross? c. What are the expected offspring phenotype classes and ratios/proportions/fractions which will result from the cross? 2. Predict ratios/proportions/fractions of genotypes and phenotypes of the following crosses. T = tall stem t = dwarf stem P = purple flowers p = white flowers G = green pods g = yellow pods A = axial flowers a = terminal flowers R = round peas r = wrinkled seeds A. ttPp x Ttpp B. GgRr x ggRr C. PpGg x ppggarrow_forwardIn tomatoes, dwarf (d) is recessive to tall (D) and opaque (light-green) leaves (op) are recessive to green leaves (Op). The loci that determine height and leaf color are linked and separated by a distance of 7 m.u. For each of the following crosses, determine the phenotypes and proportions of progeny produced.arrow_forward
- Two pure-breeding lines of petunia plants are crossed. Line 1 plants grow to a height of 54 cm, and Line 2 plants grow to a height of 18 cm. Petunia plant height is controlled by three genes, A, B and C. Line 1 has the genotype A₁A₁B₁B₁C₁C₁, and line 2 has the genotype A2A2B₂B₂C₂C₂. Assume that genotype alone determines plant height under ideal growth conditions and that the alleles of the three genes are additive. If the F1 plants are self crossed, what is the expected proportion of F2 plants with the genotype A₁A₁B₁B₁C₁C₁ 1/8 1/32 1/16 1/4 1/64arrow_forwardE. W. Lindstrom crossed two corn plants with green seedlings and obtained the following progeny: 3583 green seedlings, 853 virescentwhite seedlings, and 260 yellow seedlings . Q. Give the genotypes for the green, virescent-white, and yellow progeny.arrow_forwardA series of three-point testcrosses is made to determine the genetic map order of seven linked allele pairs: A/a, B/b, G/g, H/h, Q/q, R/r, and Y/y.From each cross between a triply heterozygous parent listed below, two recombinant classes were noticed as the least frequent among all 8 progeny classes, and are listed at the right in the table. A. For each testcross write the genotype of the F1 heterozygous parent. F1 Parental Phenotype Least frequent F2 Phenotype 1.AHB&ahb AHb & ahB 2.RYh&ryH RYH & ryh 3.BhY&bHy Bhy & bHY 4.qYB&Qyb qYb & QyB 5.AbQ&aBq Abq & aBQ 6.ghR&GHr ghr & GHR B. Write the unified map order of these genes, showing your reasoning.arrow_forward
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