Alamance BIO 111 - Genetics of Corn Experiment 1 A Monohybrid Cross

3/19/2016

Late Nite Labs

Genetics of Corn
SHORT ANSWER
Experiment 1: A Monohybrid Cross
Directions: Use complete sentences and bold the answers and have them in a different color. Failure
to do so will result in points being deducted.
Lab Results
1. What proportion of purple kernels is expected in the progeny of the monohybrid cross in Experiment 1?


2. Fill in the table below with the data you collected during Experiment 1


Purple Kernels

Yellow Kernels

Row 1





Row 2





Row 3





Row 4





Row 5





Total





Data Analysis
3. Use the data you collected in Experiment 1 to calculate the percentage of each phenotype.


4. Suppose you observed 240 progeny that resulted from a monohybrid cross and involved genes that obeyed Mendelian
inheritance, how many heterozygous progeny would you expect to observe?


Experiment 2: A Dihybrid Cross
Lab Results
1. Fill in the table below with the data you collected during Experiment 2.


Purple, Smooth Kernels

Purple, Wrinkled Kernels

Yellow, Smooth Kernels

Yellow, Wrinkled Kernels

Row 1









Row 2









Row 3









Row 4









Row 5









Total











Data Analysis
2. Fill in the following table with the percentage of each type of kernel.
Phenotype
Purple, Smooth
https://labs.latenitelabs.com/api/assessment/shortAnswer/109379/56736

Proportion of Progeny

1/4

3/19/2016

Late Nite Labs

Purple, Wrinkled



Yellow, Smooth



Yellow, Wrinkled




3. According to your results in Experiment 2, what would be the correct hypothesis to test to see if the traits were inherited
through Mendelian genetics? Record this answer for use in a later question.


4. For the cross in Experiment 2, how many degrees of freedom are there? Record this answer for use in a later question.


5. Determine the ?2 value for Experiment 2 using the following equation. Record your answer for use in a later question.
Phenotype

Observed

Expected

(O­E) 2

(O­E)

(O­E) 2/E

Purple, smooth











Purple, winkled











Yellow, smooth











Yellow, wrinkled











Sum












6. Use the degrees of freedom and ?2 value from earlier questions to determine the p value for Experiment 2 using the table
of critical values for ?2 . Record your answer for use in a later question.



Conclusions
1. Use the hypothesis, degrees of freedom, ?2 , and p value determined in earlier questions to conclude whether corn #2 is
following Mendelian genetics. Explain your reasoning.



2. If you crossed Cat #1 and Cat #2 and observed two unlinked traits that follow Mendelian genetics, what must the genotype
and phenotype of Cat #2 be?
Hair length:
Dominant = long hair (L)
Recessive = short hair (l)
https://labs.latenitelabs.com/api/assessment/shortAnswer/109379/56736

2/4

3/19/2016

Late Nite Labs

Coat color:
Dominant = white (W)
Recessive = some color (w)



3. In a test population of 1000 people, 200 display albinism. You hypothesize that this trait follows Mendelian genetics with a
3:1 ratio of non­albinism to albinism. Use the ?2 test to determine whether the data support the hypothesis or not. Show
your steps and explain your reasoning.
?2 = ? [(O – E)2 /E
where O is the observed number of individuals in a defined class, and E is the expected number of individuals in a defined
class based on the hypothesis. The ? symbol indicates that you should sum the results for each defined class.



Sources
Pierce et al., Genetics 2nd Edition.
https://labs.latenitelabs.com/api/assessment/shortAnswer/109379/56736

3/4

3/19/2016

https://labs.latenitelabs.com/api/assessment/shortAnswer/109379/56736

Late Nite Labs

4/4