1) Ants are haplodiploid organisms. This means females are diploid (2n) and males are haploid (n). The gametes produced by both males and females are haploid (n). There is no homologous recombination in males during gamete formation. There is no sex chromosome. In an ant species, it is known that wings formation (F) and setae density (D) are each controlled by a different, simple-Mendelian locus/gene. Individuals which are homozygous recessive for both genes have no wings (f) and no setae (d). Previous experiments also indicated that both loci/genes are on the same chromosome.
a. Design a test cross to map the genetic distance of the genes, by writing the genotype of the tester and its mate. (2 pts) Genotype of tester: Genotype of testerâs mate:
b. In order for the test cross to produce offspring with non-parental phenotypes, the tester has to be of a specific sex. What sex must the tester be? Briefly explain your choice in your own words. (Hint: what is a test cross?) (2 pts) Sex of tester:
c. 100 offspring were produced from a particular test cross. The phenotypic ratio of these offspring is observed to be the following:
Normal wings and setae density40
Wings and setae both absent 47
Normal wings but no setae 4
Normal setae density but no wings 9
Calculate and describe in words the genetic distance between the two loci/genes of interest. Remember to include the unit of measurement (6 pts).