7:09 PM Wed Apr 10 Three strains of green-seeded lentil plants appear to have the same phenotype. The strains are designated G1, G2, and G3. Each green- seeded strain is crossed to a purebreeding yellow-seeded strain designated Y. The F₁ of each cross are yellow; however, self- fertilization of F₁ plants produces F2 with different proportions of yellow- and green-seeded plants as shown below. Parental Strain F₁ Phenotype F2 Phenotype Green Yellow Green Yellow 1 G₁ Y All yellow 4 7 G2 Y All yellow 16 37 G3 Y All yellow 64 341626 9 27 Part A For what number of genes are variable alleles segregating in the G₁ X Y cross? Express your answer as an integer. There is/are Part B ΜΕ ΑΣΦ ? gene(s) segregating in the F2 of G₁ × Y For what number of genes are variable alleles segregating in the G2 X Y cross? Express your answer as an integer. There is/are ΜΕ ΑΣΦ ? gene(s) segregating in the F2 of G₁ × Y 42%

Red-flowering snapdragons are homozygous for allele RI. White-flowing snapdragons are homozygous for a different allele (R2). Heterozygous plants (R1 R2) bear pink flowers. What phenotypes should appear among first-generation offspring of the crosses listed? What are the expected proportions for each phenotype? a. R1R1 R1R2 b. R1R1 R2R2 c. R1R2 R1R2 d. R1R2 R2R2

Figure 12.16 In pea plants, purple flowers (P) are dominant to white flowers (p) and yellow peas (Y) are dominant to green peas (y). What are the possible genotypes and phenotypes for a cross between PpYY and ppYy pea plants? How many squares do you need to do a Punnett square analysis of this cross?

. In 1919, Calvin Bridges began studying an X-linkedrecessive mutation causing eosin-colored eyes inDrosophila. Within an otherwise true-breedingculture of eosin-eyed flies, he noticed rare variantsthat had much lighter cream-colored eyes. By intercrossing these variants, he was able to make a truebreeding cream-eyed stock. Bridges now crossedmales from this cream-eyed stock with true-breedingwild-type females. All the F1 progeny had red (wildtype) eyes. When F1 flies were intercrossed, the F2progeny were 104 females with red eyes, 52 maleswith red eyes, 44 males with eosin eyes, and14 males with cream eyes. Assume that thesenumbers represent an 8:4:3:1 ratio.a. Formulate a hypothesis to explain the F1 and F2results, assigning phenotypes to all possiblegenotypes.b. What do you predict in the F1 and F2 generations if the parental cross is between truebreeding eosin-eyed males and true-breedingcream-eyed females?c. What do you predict in the F1 and F2 generationsif the parental cross is…

. A snapdragon plant that bred true for white petals wascrossed with a plant that bred true for purple petals, andall the F1 had white petals. The F1 was selfed. Among theF2, three phenotypes were observed in the followingnumbers:white 240solid purple 61spotted purple 19Total 320a. Propose an explanation for these results, showinggenotypes of all generations (make up and explain yoursymbols).b. A white F2 plant was crossed with a solid purple F2plant, and the progeny werewhite 50%solid purple 25%spotted purple 25%What were the genotypes of the F2 plants crossed?

Nicotiana glutinosa (2 n = 24) and N. tabacum (2 n = 48) are two closely related plants that can be intercrossed, but the F1 hybrid plants that result are usually sterile. In 1925, Roy Clausen and Thomas Goodspeed crossed N. glutinosa and N. tabacum and obtained one fertile F1 plant (R. E. Clausen and T. H. Goodspeed. 1925 Genetics 10:278– 284). They were able to self-pollinate the flowers of this plant to produce an F2 generation. Surprisingly, the F2 plants were fully fertile and produced viable seeds. When Clausen and Goodspeed examined the chromosomes of the F2 plants, they observed 36 pairs of chromosomes in metaphase I and 36 individual chromosomes in metaphase II. Explain the origin of the F2 plants obtained by Clausen and Goodspeed and the numbers of chromosomes observed.

Summer squash exist in long, spherical, or disk shapes. When atrue-breeding long-shaped strain was crossed to a true-breedingdisk-shaped strain, all of the F1 offspring were disk-shaped. Whenthe F1 offspring were allowed to self-fertilize, the F2 generationconsisted of a ratio of 9 disk-shaped to 6 round-shaped to 1 longshaped. Assuming the shape of summer squash is governed by twodifferent genes, with each gene existing in two alleles, propose amechanism to account for this 9:6:1 ratio

Monohybrid Cross: 1) In dogs, wire hair (S) is dominant to smooth (s). a. In a cross between a homozygous wire-haired dog with a smooth haired dog what are the genotypes and phenotypes of the F1 generation? b. If a brother and sister from the F1 generation are crossed what is the expected ratio of wire-haired to smooth-haired dogs produced from this cross?

Mendelian GeneticsF1 Cross: Yellow, Round x Green, Round GgWw x ggWWCharacter: Pea color & shapeUse Punnett square and fork-line method to check the F2.Show and interpret all the possible genotypes and phenotypes of the offsprings. Mendelian GeneticsF1 Cross: Tall, White, Axial x Dwarf, Violet, Terminal DdwwAA x ddWWaaCharacter: Stem height, Flower color & positionUse fork-line method to check the F2.Show and interpret all the possible genotypes and phenotypes of the offsprings. I. For A and B,1. Identify the type of inheritance. Justify your answer.2. Decode the genotypes of the individuals in the pedigree. (Use letter A for representation of alleles.)3. List down all affected individuals.B.A.

Assume that there is complete interference in the Lf-W region. The cross between the triple heterozygote (Lf J W/ lf j w) and a triple homozygous recessive produced 350 progenies. Give the frequency of each specific progeny type:a. with crossover in the Lf-J and J-W regionsb. with crossover in the Lf-J regionc. with crossover in the J-W regiond. without crossover in the Lf-W region