This document summarizes a genetics lab experiment conducted with fruit flies. The experiment aimed to observe principles of dominance, segregation, independent assortment, and sex linkage. F1 generation flies showed a wildtype phenotype, while F2 generation flies showed wildtype, yellow, vestigial, and yellow/vestigial phenotypes. A chi-square analysis found the results inconsistent with the hypothesis, suggesting misidentification of phenotypes as the likely explanation rather than disproving Mendelian genetics.

1. Juan Barrera
Mandira Lamichhane
Unknown: W4
Genetics Lab 3103
Fall 2013
https://fbexternal-a.akamaihd.net/safe_image.

2.  Observe and analyze the principles of Dominance, Segregation,
and Independent Assortment.
 Observe and analyze sex linkage.
 Use forward genetics to predict parental Generation.
 Create branch diagram to predict phenotypic ratios and create
hypothesis.
 Use of chi-square analysis for hypothesis validation.
http://www.ourhonordefend.comhttp://www.nobelprize.org

3.  Given unknown W4, F1 Generation flies.
 Observed F1 phenotypes
 Set up 8 vials with media
 Placed flies in vials
 Allowed F1 flies to mate and create F2 offspring
 Observed F2 phenotypes
 Used forward genetics to predict Parental
Generation.
 Created branch diagram to make F2 phenotypic
ratio and hypothesis.
 Used Chi-Square analysis to test hypothesis.

4.  F1 Generation flies were observed to be “Wildtype”. Normal
bodies, normal eyes, normal wings.
 F2 Generation flies were observed to be a mixture of Wildtype,
Yellow, Vestigial, and both Yellow and Vestigial flies.

9. Degrees of Freedom n-1= 3
7.815
The chi-square is more than the
critical value, therefore there is
less than 5% probability that this
can occur, the difference
between expected and observed
data is not due to chance and
the result is inconsistent with
our hypothesis. We therefore
reject our hypothesis. The same
can be said about the chi-square
analysis for both males and
females with the chi-square
value being more than 7.815.

10.  What do the results
mean?
 Did we disprove
Mendelian genetics???
 Yellow Females!?!?!?
 Could be do to
misidentification.