Biology 22
Drosophila
Identification of various
phenotypes.
DATA POSTED FOR TWO EXPERIMENTS

1. Various Drosophila crosses and number
of flies with the phenotypes of body color
and gender of same fly.

2. Three-point test cross: look at three
different phenotypes on the same fly; wing
length, body color and eye color.
Experiment 1. Parental phenotypes
Experiment: body color
A= female: wt (beige)
 B=female: wt (beige)
 C=male: wt (beige)
 D=female: mutant (yellow)
 E=male: mutant (yellow)

What are the color and gender of
each fly? Note: data recorded
body color
 gender

Wild Type Versus Mutants

Body Color
Wild type: Beige
 Mutant: Yellow body

Fruit Fly Body Color
Experiment 2: 3 point test cross:

Experiment 2

3 point test cross
Eye color
 Body color
 Wing length

3 point test cross for:
♦ Wt
vs.
Mutant
1. Body Color
Beige (bl+) vs. Black (bl)
2. Wing length
Long(vg+) vs. Vestigal(vg)
3. Eye Color
Brick red (br+) vs. brown (br)
Crosses:
Female

Males
bl+ vg+ bw+
bl vg br
X
bl vg

bw
bl vg br
Males and female progeny from this F2 cross
are your 3 point test cross results!
Fruit Fly Wings
Eyes
Lab Report

Experiment 1: Use the data to calculate
Chi-Square analysis to determine if
observed versus expected supports or rejects
the Ho (null hypothesis).

Experiment 2: Use the data to determine the
arrangement of the 3 genes for body color,
eye color and wing length.
Lab Report

Use the data provided to fill in the tables
(provided in the lab manual) and perform the
calculations required.

Lab report is can be handed in May 29th (one
week later)