1. Drosophila Lab: Exploring Genetics
AP recommended lab

2. Two Tasks to Complete Pre-lab Questions from 12 Recomm. Labs
(link from my website)
Computer Simulated Lab: “Gene Pool” drive
***Answer Questions on a separate paper.

3. To Access the Lab Simulation for Drosophila
Click the “START” and choose “My Computer”
Type in the following:
\\trhs_math_lang\genepool$
Choose the “Drosophila folder” and double click the “Neo” application.
Follow the instructions and answer the guiding questions listed on the front page of your lab.

4. Key Parts for Drosophila Lab
Stages of Drosophila
Main Characteristics to observe (4)
Determining Male vs. Female (3)
Examine 3 Modes of Inheritance:
Monohybrid: Red Eyes x Sepia Eyes
Dihybrid: Eye color, Wing
Sex-Linked: White eyed-female x Red eyed Male
(X? X ? ) • (X ? y )

5. Observed Values Table 7.2: F2 Generation -78 red-eyed females
-62 white-eyed females
-69 red-eyed males
-73 white eyed males
Expected Results: Complete #3 (both Tables)
Do a Chi-square analysis.
**Note: Critical values are listed in Table 7.5 on the bottom of Page 86.

6. Crosses to Complete for Lab #6
Table 7.1: F1 Generation Data
Phenotype and Symbol
Females
Males
Red-eyed
all XRXr
White-eyed
all XrY

7. F2 Generation: Sex-Linked trait
Phenotype and Symbol
Females
Males
Red-Eyed (XR)
78 XRXr
69 XRY
White-Eyed (Xr)
62 XrXr
73 XrY
Assume that the following Data was obtained and determine if it is significant or not by calculating a Chi-Square value.

8. Answer for First Cross X2 = (78-72) 2 + (69-71)2 + (62-71)2 + (73-71)2
X2 =
X2 = 1.94
Degrees of freedom: (4 categories)
Critical Value: see Table7.3 (pg.85)
The chi-squared value is less than 7.82
Therefore:Our null hypothesis is accepted: That there is not a significant difference between the observed value and expected value. We must then accept that our results follows the expected (theoretical value).

9. 2nd Genetic Cross Red-Eyed: Dominant S Sepia eyes: Recessive s
Parental cross: SS X ss
F1 Cross: Ss X Ss
F1: All Ss
F2: :1 (red:sepia)

10. Observed Values for #7 (table)
Phenotype # Observed # Expected
Red-Eyed calc. value
sepia calc. Value
Total: offspring
Complete Questions #6 & 7

11. Data for Second Cross (o-e) (o-e)2 e Red 140 Sepia 60 Phenotype
# observed (o)
# Expected (e)
(o-e)
(o-e)2 e
Red
140
Sepia 60

12. Other Crosses to do Pg 86: Green & Albino seedlings
Pg.88: Long & short winged flies
**complete and calculate Chi-Square values to determine if the results are significant and acceptable (statistically valid)