DROSOPHILA WILD TYPE AND DROSOPHILA SEPIA
F1 AND F2 CROSSES
BY ALI NANEZ, FORREST CLARK, LAUREN CUDDIHY
BACKGROUND INFORMATION
• Drosophila Melanogaster
• Africa to USA
• Quick experiments, low cost, short life cycle
• Gene arrangement contribute to biological functions
• Mutation interaction
• They use fundamental processes to which body structure forms
INTRODUCTION
• Cross two different species of fruit flies
• First cross: Drosophila Curly Plum and Apterous (died)
• Second cross: Drosophila Wild Type and Sepia
• WT had autosomal dominant trait of red eyes
• Sepia had autosomal recessive trait of brown/black eyes
F1 HYPOTHESIS
• F1 Hypothesis: All of our off spring will have red eyes and carry the brown eye gene.
r
r
R
Rr
Rr
R
Rr
Rr
Key
R = red eyes
r = brown/black eyes
F2 HYPOTHESIS
• F2 Hypothesis: 42 observed flies will result by having a ratio of red to black/brown eyes of 3:1.
R
r
R
RR
Rr
r
Rr
rr
Key
R = red eyes
r = brown/black eyes
METHODS/EXPERIMENTAL DESIGN
Fly Incubator
•
Two vials with food
•
3 female Sepia, 3 WT male each vial
•
Obtained our F1 generation to crossed the
offspring
•
Incubated the flies for new crosses
•
Obtained our F2 generation from F1 crosses
•
Counted and studied
Fly Nap
Vial with food
FIGURES/GRAPHS/TABLES
Red eyes
Brown/black eyes
Total
Observed
37
5
42
Expected (3:1 ratio)
31.5
10.5
0.96031746
2.880952381
Chi Squared value/Sample value
3.841269841
Critical Value
3.841
RESULTS
• Since our sample value is was the same as the critical value, we decided that we failed
to reject our hypothesis.
• Sample Value: 3.841
• Critical Values: 3.841
RESULT PICTURES
F2 Red Eyed Flies
F2 Black/Brown Eyed Flies
F2 Black and Red Eyed Flies
SOURCES
•
Drosophila. (2010, January). In Bench Fly. Retrieved September 28, 2016, from
http://www.benchfly.com/blog/wp-content/uploads/2010/01/Drosophila.jpg
•
Facility, M. F. (Director). (2014, December 20). Drosophila: Small fly, BIG impact - Part 1 (Why the fly?) [Video
file]. In Drosophila: Small Fly, BIG Impact - Part 1 (Why the Fly?). Retrieved September 27, 2016, from
www.youtube.com/watch?V=qDbJnFlI3kU
•
Flagg, R. O. (2005). Carolina drosophila manual. Burlington, NC: Carolina Biological Supply.
•
Wild Type. (n.d.). In Farm 4 Static Flickr. Retrieved September 28, 2016, from
https://farm4.staticflickr.com/3935/15460693815_2d1bc0500b_b.jpg
Questions?