Question

on the basis of mendel hypothesis and predictions predict the result from the followingcrosses in garden pea : (a) a tall (dominant and homozygous ) variety crossed with dwarf variety , (b) the progeny of (a) selfed, (c) the progeny from (a) crossed with original tall parent , (d) the progeny from (a) crossed with original dwarf paren t variety.PLZ HELP ME

Answer 1

Chapter 33.1On the basis of Mendel’s observations, predict the results from the followingcrosses with peas: (a) a tall (dominant and homozygous) variety crossed with a dwarfvariety; (b) the progeny of (a) self-fertilized; (c) the progeny from (a) crossed with theoriginal tall parent; (d) the progeny of (a) crossed with the original dwarf parent.ANS:(a) All tall; (b) 3/4 tall, 1/4 dwarf; (c) all tall; (d) 1/2 tall, 1/2 dwarf.3.2Mendel crossed pea plants that produced round seeds with those that producedwrinkled seeds and self-fertilized the progeny. In the F2, he observed 5474 round seedsand 1850 wrinkled seeds. Using the letters Wand wfor the seed texture alleles, diagramMendel’s crosses, showing the genotypes of the plants in each generation. Are the resultsconsistent with the Principle of Segregation?ANS:Round (WW) x wrinkled (ww) ---> F1 round (Ww); F1 self-fertilized ---> F2 3/4round (2 WW; 1 Ww), 1/4 wrinkled (ww). The expected results in the F2 are 5493 round,1831 wrinkled. To compare the observed and expected results, compute 2 with onedegree of freedom; (5474 – 5493)2/5493 = (1850 – 1831)2/1831 = 0.263, which is notsignificant at the 5% level. Thus, the results are consistent with the Principle ofSegregation.3.3A geneticist crossed wild, gray-colored mice with white (albino) mice. All theprogeny were gray. These progeny were intercrossed to produce an F2, which consisted of198 gray and 72 white mice. Propose an hypothesis to explain these results, diagram thecrosses, and compare the results with the predictions of the hypothesis.ANS:The data suggest that coat color is controlled by a single gene with two alleles, C(gray) and c(albino), and that Cis dominant over c. On this hypothesis, the crosses are: