AP Biology Lab 7: Genetics of Organisms Computer Questions

 

LAB A

IDENTIFICATION OF WILD-TYPE CHARACTERS AND SEX IN DROSOPHILA MELONGASTER

 

  1. Describe male Drosophila characteristics:

 

 

ANSWER

DRAWING WITH LABELS

1. Describe the male Drosophila characteristics

 

 

 

 

 

 

2. Describe female Drosophila characteristics

 

 

 

 

 

 

3. Describe wild-type Drosophila characteristics

 

 

 

 

 

 

 

LAB B

EXAMINATION OF THE F1 HYBRIDS AND THE F2 GENERATION

 

  1. What is the phenotypic ratio you would expect to see in the F2 generation (dihybrid) if you were following.
    1. A sex linked trait _____________

 

    1. An autosomal trait ____________

 

    1. Two autosomal dominant characters (dihybrid cross) ___________

 

 

  1. What is a critical p value, and how is it used in a Chi-square test?

 

 

  1. What does a probability level of 0.05 mean?

 

 

CROSS 1: SEPIA EYES x WILD TYPE EYES

 

F1 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

F2 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

 

QUESTIONS:

  1. Based on your observations of the F2 generation, what type of inheritance pattern do you think you have observed? (HINT: simple dominance/recessive, autosomal/sex linked, monohybrid/dihybrid)

 

 

 

 

  1. In order to statistically analyze the results of this cross and have something meaningful to compare those results against, you must first formulate a null hypothesis. A null hypothesis (Ho) assumes that there is no difference between the observed results and the expected results based on your assumption of the type of inheritance pattern you observed. Restate your guess about the type of inheritance pattern you observed (from question #1) as null hypothesis.

 

 

 

 

 

 

 

  1. Based on your null hypothesis and your assumption of the type of inheritance pattern you observed, construct a Punnett square for the F1 generation.

 

 

 

 

 

 

  1. The Chi-square test can be used to determine whether you observed results from the cross are a good match with your expected results. Therefore, you first need to determine what to expect results should be. Using the Punnett squares you constructed, list the ratios for your expected results of the F1 and G2 generations below.
    1. F1 expected genotypic ratio _______________________

 

    1. F1 expected phenotypic ratio _______________________

 

    1. F2 expected genotypic ratio ______________________

 

    1. F2 expected phenotypic ratio ______________________

 

  1. Based on your null hypothesis and your assumptions of this type of inheritance pattern you observed, construct a Punnett square for the Parental (P) generation.

 

 

 

 

 

  1. Examination of the F1 hybrids and the F2 generation. Complete the following chart to determine if any deviation from the expected F2 results is due to random chance. Can you support your null hypothesis or reject it?

 

Phenotypic Classes

# observed

# expected

(O-E)2

     E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

∑ =

 

X2 = __________                  df = ___________

 

P= ___________      critical p value = __________

 

Based on this information, do you accept or reject your null hypothesis ? _________________

 

 

 

CROSS 2: White males x Wild-type females

 

F1 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

F2 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

 

QUESTIONS:

  1. Based on your observations of the F2 generation, what type of inheritance pattern do you think you have observed? (HINT: simple dominance/recessive, autosomal/sex linked, monohybrid/dihybrid)

 

 

 

 

  1. In order to statistically analyze the results of this cross and have something meaningful to compare those results against, you must first formulate a null hypothesis. A null hypothesis (Ho) assumes that there is no difference between the observed results and the expected results based on your assumption of the type of inheritance pattern you observed. Restate your guess about the type of inheritance pattern you observed (from question #1) as null hypothesis.

 

 

 

 

 

 

 

  1. Based on your null hypothesis and your assumption of the type of inheritance pattern you observed, construct a Punnett square for the F1 generation.

 

 

 

 

 

 

  1. The Chi-square test can be used to determine whether you observed results from the cross are a good match with your expected results. Therefore, you first need to determine what to expect results should be. Using the Punnett squares you constructed, list the ratios for your expected results of the F1 and G2 generations below.
    1. F1 expected genotypic ratio _______________________

 

    1. F1 expected phenotypic ratio _______________________

 

    1. F2 expected genotypic ratio ______________________

 

    1. F2 expected phenotypic ratio ______________________

 

  1. Based on your null hypothesis and your assumptions of this type of inheritance pattern you observed, construct a Punnett square for the Parental (P) generation.

 

 

 

 

 

  1. Examination of the F1 hybrids and the F2 generation. Complete the following chart to determine if any deviation from the expected F2 results is due to random chance. Can you support your null hypothesis or reject it?

 

Phenotypic Classes

# observed

# expected

(O-E)2

     E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

∑ =

 

X2 = __________                  df = ___________

 

p= ___________      critical p value = __________

 

Based on this information, do you accept or reject your null hypothesis ? _________________

 

CROSS 3: Vestigial wings x Sepia Eyes

 

F1 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

F2 Generation Drosophila melongaster characters

Description of Phenotypic Character

# Males

# Females

Total

 

 

 

 

 

 

 

 

 

 

 

 

 

QUESTIONS:

  1. Based on your observations of the F2 generation, what type of inheritance pattern do you think you have observed? (HINT: simple dominance/recessive, autosomal/sex linked, monohybrid/dihybrid)

 

 

 

 

  1. In order to statistically analyze the results of this cross and have something meaningful to compare those results against, you must first formulate a null hypothesis. A null hypothesis (Ho) assumes that there is no difference between the observed results and the expected results based on your assumption of the type of inheritance pattern you observed. Restate your guess about the type of inheritance pattern you observed (from question #1) as null hypothesis.

 

 

 

 

 

 

 

  1. Based on your null hypothesis and your assumption of the type of inheritance pattern you observed, construct a Punnett square for the F1 generation.

 

 

 

 

 

 

  1. The Chi-square test can be used to determine whether you observed results from the cross are a good match with your expected results. Therefore, you first need to determine what to expect results should be. Using the Punnett squares you constructed, list the ratios for your expected results of the F1 and G2 generations below.
    1. F1 expected genotypic ratio _______________________

 

    1. F1 expected phenotypic ratio _______________________

 

    1. F2 expected genotypic ratio ______________________

 

    1. F2 expected phenotypic ratio ______________________

 

  1. Based on your null hypothesis and your assumptions of this type of inheritance pattern you observed, construct a Punnett square for the Parental (P) generation.

 

 

 

 

 

  1. Examination of the F1 hybrids and the F2 generation. Complete the following chart to determine if any deviation from the expected F2 results is due to random chance. Can you support your null hypothesis or reject it?

 

Phenotypic Classes

# observed

# expected

(O-E)2

     E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

∑ =

 

X2 = __________                  df = ___________

 

p= ___________      critical p value = __________

 

Based on this information, do you accept or reject your null hypothesis ? _________________