DROSOPHILA GENETICSUNIT 3: FRUIT FLY EXPERIMENT

OCTOBER 2ND-NOVEMBER 6TH

Juan BarreraMandira Lamichhane

Unknown: W4

Genetics Lab 3103Fall 2013

https://fbexternal-a.akamaihd.net/safe_image.

Purpose 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.com

http://www.nobelprize.org

Experiment Overview 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.

Observations 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.

Hypothesis/Prediction

Hypothesis/Prediction

Hypothesis/Prediction

Results

ConclusionDegrees of Freedom n-1= 37.815

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.

Discussion What do the results

mean? Did we disprove

Mendelian genetics???

Yellow Females!?!?!?

Could be do to misidentification.