1. MAKING PUNNETT PREDICTIONS

2. m m + +m +m + m + ++ +m m +m mm F1 All = +m (show wildtype phenotype)
IF GENE is AUTOSOMAL and RECESSIVE TO WILD TYPE (+)
MALES:FEMALES 1:1
+m +m F1
All = +m (show wildtype phenotype) m + m F2
¼ = % wildtype
½ = +m
¼ = mm % mutant
3:1 ratio
++ +m
+m mm

3. M M + +M +M + M + ++ +M M +M MM F1 All = +M (mutant) F2
IF GENE is AUTOSOMAL and DOMINANT TO +
MALES:FEMALES 1:1
M M +
+M +M F1
All = +M (mutant) M + M F2
¼ = % wildtype
½ = +M
¼ = MM % mutant
1:3 ratio
++ +M
+M MM

4. X Y y y Yy yy Y y Y YY Yy y Yy yy Some disorders (YY) is lethalF1
Some disorders (YY) is lethal
IF GENE is LETHAL (YY)
(Can’t cross pure dominant)
Males:females 1:1
Y y y
Yy yy F1
50% = Yellow
50% = grey F2
Y y Y y F2
¼ = YY (lethal)
½ = Yy /3 yellow
¼ = yy /3 grey
2:1 ratio
YY Yy
Yy yy X

5. Xm y X+ y Xm X+ X+Xm X+y X+Xm Xmy Xm XmXm Xmy
IF GENE is X-LINKED RECESSIVE
Different pattern if gene is inherited from mom or dad
Mutant mom X wild type dad F1 F1
Xm y X+ Xm
X y Xm
X+Xm X+y
XmXm Xmy
X+Xm Xmy
50% normal females
50% mutant males
25% normal females 25% mutant females % mutant males 25% normal males
When using Virtual fly lab Choose ignore sex and see if it changes the ratios

6. X+ y Xm y X+ X+ X+Xm X+y X+Xm X+y Xm X+Xm Xmy
IF GENE is X-LINKED RECESSIVE
Different pattern if gene is inherited from mom or dad
Wild type mom X mutant dad F1 F2
X y X+ Xm
Xm y X+
X+Xm X+y
X+Xm Xmy
X+Xm X+y
50% normal females
50% normal males
50% normal females % mutant males 25% normal males
When using Virtual fly lab Choose ignore sex and see if it changes the ratios

7. XM y X+ y XM X+ X+XM X+y X+XM XMy XM XMXM XMy
IF GENE is X-linked dominant
MUTANT MOM X WILD TYPE DAD F1 F2
XM y X+ XM
X y XM
X+XM X+y
XMXM XMy
X+XM XMy
50% mutant females 50% mutant males
50% mutant females 25% wild type males 25% mutant males
When using Virtual fly lab Choose ignore sex and see if it changes the ratios

8. X+ y XM y X+ X+ X+X+ X+y X+XM X+y XM X+XM XMy
IF GENE is X-linked dominant
WILD TYPE MOM X MUTANT DAD F1
X y X+ XM
XM y X+ F2
X+X+ X+y
X+XM XMy
X+XM X+y
50% mutant females
50% normal males
25% wild type females 25% mutant females 25% wild type males 25% mutant males
When using Virtual fly lab Choose ignore sex and see if it changes the ratios

9. GENETIC ABBREVIATIONS DOMINANT MUTATIONS: first letter = capitalized.
EX: sternopleural bristles= Sp
RECESSIVE MUTATIONS = lower case
EX: mahogany eyes = mah
normal "wild type" version of the gene = same abbreviation as mutant with a "+" superscript
For example, Sp+ and mah+.
Sometimes, when the meaning is obvious, "+" by itself is used
EX: heterozygote genotypes: +/Sp and +/mah.
VIRTUAL FLY LAB DOESN’T FOLLOW THIS PROTOCOL: You need to explore and figure out whether it is dominant or recessive.