The following progeny are obtained from a testcross of a trihybrid wild-type plant to a plant with the recessive phenotypes compound leaves (c), intercalary leaflets (i), and green fruits (g) (Traits not listed are wild types). The testcross progeny are as follows:
Phenotype
Number
Compound leaves
324
Compound leaves, intercalary leaflets
32
Compound leaves, green fruits
5
Compound leaves, green fruits, intercalary leaflets
51
Intercalary leaflets
3
Green fruits
42
Wild type
49
Intercalary leaflets, green fruits
309
815
Determine the order of the three genes, and construct a genetic map that identifies the correct order and the alleles carried on each chromosome in the trihybrid parental plant. Calculate the frequency of the recombination between the adjacent genes in the map. How many double cross-over progeny are expected among the test-cross progeny? Calculate the interference for this cross.
The following progeny are obtained from a testcross of a trihybrid wild-type plant to a plant with the recessive phenotypes compound leaves (c), intercalary leaflets (i), and green fruits (g) (Traits not listed are wild types). The testcross progeny are as follows:
| Phenotype | Number |
| Compound leaves | 324 |
| Compound leaves, intercalary leaflets | 32 |
| Compound leaves, green fruits | 5 |
| Compound leaves, green fruits, intercalary leaflets | 51 |
| Intercalary leaflets | 3 |
| Green fruits | 42 |
| Wild type | 49 |
| Intercalary leaflets, green fruits | 309 |
| 815 |
Determine the order of the three genes, and construct a genetic map that identifies the correct order and the alleles carried on each chromosome in the trihybrid parental plant. Calculate the frequency of the recombination between the adjacent genes in the map. How many double cross-over progeny are expected among the test-cross progeny? Calculate the interference for this cross.
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In a plant leaf color, leaf shape, and plant height are controlled by three linked genes. Wildtype plants are normal height with pointed, green leaves. Triple mutant plants are dwarf (d) with round (r), white (w) leaves. A female heterozygous for all three mutations is testcrossed and the following progeny phenotypes were observed:
| wildtype | 116 |
| dwarf | 350 |
| dwarf, round | 4 |
| dwarf, round, white | 120 |
| round, white | 325 |
| round | 35 |
| white | 3 |
| dwarf, white | 47 |
a. What are the parental genotypes?
b. Which gene is in the middle?
c. Construct a genetic map showing distances between adjacent genes.
d. Calculate the interference observed in this cross.
In Drosophila, the map positions of genes are given in map units numbering from one end of a chromosome to the other. The X chromosome of Drosophila is 66 m.u.. long. The X-linked gene for body color-with two alleles, y +for gray body and y for yellow body-resides at one end of the chromosome at map position 0.0. A nearby locus for eye color, with alleles w +for red eye and w for white eye, is located at map position 1.5. A third X-linked gene, controlling bristle form, with f + for normal bristles and f for forked bristles, is located at map position 56.7. Each gene resides on the Xchromosome, and at each locus the wild-type allele is dominant over the mutant allele.
Predict the frequency of gray with white eyes and forked bristles progeny type produced by this mating.
Enter your answer as a percentage to three decimal places (example 0.235 or 0.230).
Frequency=_________
2.
| Phenotype | Number |
| Pale | 648 |
| Pale, oval | 64 |
| Pale, short | 10 |
| Pale, oval, short | 102 |
| Oval | 6 |
| Oval, short | 618 |
| Short | 84 |
| Wild type | 98 |
| 1630 |
A wild-type trihybrid soybean plant is crossed to a pure-breeding soybean plant with the recessive phenotypes pale leaf l, oval seed (r), and short height (t). The results of the three-point test cross are shown in the table. Traits not listed are wild type.
Calculate the interference value for these data.
Enter your answer to three decimal places (example 0.201).
