1. 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

2. Series 1: Autosomal Unlinked
Male Parent
genotype
+/+ ; +/+
dpy/dpy; unc/unc
Hermaphrodite
Parent genotype X
Hermaphrodite
gametes
Male gametes
F1 Progeny genotypes
F1 Progeny phenotypes
and ratios
Which progeny are you continuing with? Why?

3. Series 1: Autosomal Unlinked
F1 parent X
self cross
F1 gametes
students can show Punnet Square
F2 Progeny genotype
F2 Progeny phenotypes
and ratios

4. Series 1: Autosomal Linked
Male Parent
genotype
+ + / + +
dpy unc/dpy unc
Hermaphrodite
Parent genotype X
Hermaphrodite
gametes
Male gametes
F1 Progeny genotype
F1 Progeny phenotypes
and ratios
Which progeny are you continuing with? Why?

5. F1 parent X
self cross
F1 gametes
F2 Progeny genotype
F2 Progeny phenotypes
and ratios

6. Series 1: One Autosomal, One x-linked
gene-1/gene1; x-gene2/x-gene2
Male Parent
genotype
+/+ ; +/0 X
Hermaphrodite
Parent genotype
Hermaphrodite
gametes
Male gametes
F1 Progeny genotype
F1 Progeny phenotypes
and ratios
With which progeny are you continuing? Why?

7. Series 1: One Autosomal, One x-linked
F1 parent X
self cross
F1 gametes
F2 Progeny genotypes
F2 Progeny phenotypes
and ratios