Fisher
Name:____________________
Date:_____________________
Period:____________________
Chapter 6 Genetics Lab
“Breeding Mutations In Fruit Flies; Drosophila melanogaster”
Instructions:
Go to my website
Click on link “Biology Textbook Online Classzone”
Click on “Virtual Labs” link
Click on “Breeding Mutations in Fruit Flies”
Problem:
In this investigation you will work with a series of fruit flies called Drosophila melanogaster.
You will cross tan-colored wild-type fruit flies with ebony-colored (black) mutant fruit flies to
help you understand how some traits are inherited from one generation to the next.
Data Collection Observations:
P Generation
Wild Type
Ebony-Bodied
Males
Females
Eye color
Eye Shape
Wing Shape
Body Color
Results of First Cross (F1 Generation)
Phenotype
Tan Female
Tan Male
Ebony-Bodied Female
Ebony-Bodied Male
Number of Flies
F1 Generation
Males
Females
Second Cross (F2 Generation)
F1 female with an F1 male
Predict the Ratio…
Ratio of number of flies of each phenotype:
Males Tan Body:________
vs. Males Ebony Body_________
Females Tan Body:_______ vs. Females Ebony Body________
Results of Second Cross (F2 Generation) F1 female x F1 male
Phenotype
Tan Female
Tan Male
Ebony-Bodied Female
Ebony-Bodied Male
Number of Flies
Analyze Your Data/ Draw Conclusions:
1. Describe the differences in body color observed in the F1 and F2 generations.
2. Construct a Punnett Square to show the original cross between the tan fruit fly and the
ebony fruit fly.
T
T
e
e
What is the genotype ratio of the F1 generation?
What is the phenotype ratio of the F1 generation?
3. Construct a Punnett Square to show the second cross.
T
e
T
e
What is the genotypic ratio of the F2 offspring?
What is the phenotypic ratio of the F2 offspring?
4. Infer is the trait for ebony body color recessive or dominant? How can you tell?
5. Why did the ebony body color disappear in the F1 generation and reappear in the F2
generation?