Two true-breeding varieties of maize, one 11 cm high and the other 47 cm high were crossed and the resultant Fı 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. 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. «

A plant geneticist is examining the mode of inheritance of flower color in two closely related species of exotic plants.  The first species may have two pure-breeding lines—one produces a distinct red flower; and the other produces flowers with no color at all, or very pale yellow flowers.  However, she cannot be sure.  A cross of these varieties produces all pink-flowered progeny.  The second species exhibits similar pure-breeding varieties; that is, one variety produces red flowers; and the other produces an albino or very pale yellow flower.  A cross of these two varieties, however, produces orange-flowered progeny exclusively.  Analyze the mode of inheritance of flower color in these two plant species.

You have already localized the genes to the same chromosome by deletion mapping, and now decide that the best way to accomplish the mapping is to conduct two simultaneous three-point testcross experiments. The genes you are investigating are as follows: N = round leaves, n = notched leaves; H = smooth stems, h = hairy stems; R = purple flowers, r = red flowers; B = grey seeds, b = black seeds; and Y = green pods, y = yellow pods. Earlier experiments you have done already established that gene B is in the middle of this gene cluster, so you design both three-point test crosses to include that gene. Cross #1 is designed as RrHhBb x rrhhbb while cross #2 is NnBbYy x nnbbyy. The results of both crosses are given in the table below. Based on the information given, determine the arrangement of these five genes including the position of each allele in the heterozygous fly and the distances between each pair of genes. (Hint: treat each experiment separately, knowing that gene B is in the…

In cucumbers, speckled fruit color (u') is dominant to uniform fruit color (u), and large spines (ss") are dominant to small spines (ss). These two genes are linked at a map distance of 20.4 m.u. A true-breeding cucumber plant with speckled fruit and large spines is crossed with a true-breeding plant with uniform fruit color and small spines. One of the F1 plants is crossed with a plant with uniform fruit color and small spines. What percentage of the offspring of this cross are expected to have uniform fruit color and small spines? 39.8% 10.2% 79.6% 20.4%