Download Fruit Fly Lab Write Up Template File - District 196 e

Part One: Introduction
The common fruit fly, Drosophila melanogaster had been used in genetics studies
for years. One of the first geneticists to use fruit flies was Thomas Hunt Morgan
back in early 1900s. Fruit flies make good subjects for studying genetics because…
Fruit flies life cycle begins with… In lab we studied 3 crosses; monohybrid, dihybrid,
and sex-linked.
Part Two: Lab Work
A. Monohybrid Cross
a. Description of Cross
i. Trait studied: eye color
ii. P generation was crossed and the F2 generation was observed.
iii. In fruit flies, wild eye (red color) trait is dominant while the
sepia eye (brown color) trait is recessive.
iv. The genotypes of the P generation fruit flies crossed are
homozygous wild eye (RR) crossed with a homozygous sepia eye
(rr).
b. Hypothesis
i. If homozygous wild eye fruit flies are crossed with homozygous
sepia eye fruit flies in the P generation then a ratio of… will be
observed in the F2 generation.
c. Data Chart
Wild Eye
Sepia Eye
Group Data:
Class Data:
1539
592
d. Chi Square Results
i. Chi square results class data =
B. Dihybrid Cross (use same format as shown above)
a. Description of Cross
b. Hypothesis
c. Data Chart
C. Sex-Linked Cross (use same format as shown above)
a. Description of Cross
b. Hypothesis
c. Data Chart
Part Three: Conclusion
According to Gregor Mendel, the Law of dominance… the Law of Segregation… The
Law of Independent Assortment… These laws were used to predict the outcomes of
the genetic crosses studied in class. In the monohybrid cross, our group hypotheses
a 3 to 1 ratio of wild eye to sepia eye in the F2 generation. Our hypothesis was
based on Mendel’s Law of Segregation. A Chi square value of … for the group data
shows there is no significant difference between the observed and expected
frequencies, therefore our hypothesis is accepted. In the dihybrid cross…