Symbols to Know for Crosses a/a – a is the allele and / represents the two chromatids – there are two alleles for a diploid organism a b/a b – two different genes on the same chromosome a/a ; b/b – two different genes on different chromosomes ; designated separate chromosomes X – symbolizes mating between two different individuals X - symbolizes a self cross – when the hermaphrodite worms fertilize their own eggs + is the wild type or non-mutant form of a gene

Creating a heterozygous male Male Parent genotype Hermaphrodite Parent genotype X Female gametes Male gametes Progeny genotype Progeny phenotypes and ratios Which progeny are you continuing with? Why?

Linkage 1: Cross with Unlinked unc Male Parent genotype +/+ ; unc/unc Hermaphrodite Parent genotype X Female gametes Male gametes F1 Progeny genotype and ratios F1 Progeny phenotypes

Linkage 2: Selfing of hermaphrodite from unlinked cross X self cross gametes Progeny genotype Progeny phenotypes and ratios

Linkage 1: Crossing with Linked unc Male Parent genotype + unc/ + unc Hermaphrodite Parent genotype X Female gametes Male gametes Progeny genotype Progeny phenotypes and ratios Which progeny are you continuing with? Why?

Linkage 2: Selfing of hermaphrodite from linked cross X self cross gametes Progeny genotype Progeny phenotypes and ratios

Mapping 1: Making the double mutant hermaphrodite X self cross gametes Progeny genotype Progeny phenotypes and ratios What if the genotype of the parent was + unc/+ unc?

Mapping 2: Making heterozygotes for mapping Male Parent genotype Hermaphrodite Parent genotype X Female gametes Male gametes Progeny genotype Progeny phenotypes and ratios Why might you see Dpy Unc progeny?

Mapping 3: Test Cross Hermaphrodite Male Parent Parent genotype X Parental Recombinant Female gametes Male gametes Progeny genotype Progeny phenotypes and ratios