Name:___________________________
Lab: Inherited Traits in Corn
Worksheet is worth 15 points with the following breakdown. Partial credit was given for
all sections except fill in the blank if students made an honest effort to answer the
question.



Fill in the blank: 7 points ( one per question)
Expected Results for Crossing Two F1 plants: 2 points
Observed Results:
Question 1: 1 point
Question 2: 1 point
Question 3: 1 point
Question 4: 2 points
Genetic Terminology: Fill in the Blank
1. Genetics is the scientific study of heredity.
2. A trait is an observable difference between individuals that varies such as hair or eye
color.
3. Genes are the chemical factors that determine traits.
4. Alleles are different forms of a single gene.
5. If an allele is dominant, any individual with that allele will exhibit that trait.
6. If an allele is recessive, an individual will only exhibit the trait specified by that allele if
there are no dominant alleles present.
7. A genotype describes what alleles were inherited from each parent, while a phenotype is
the observed trait resulting from that inheritance.

Word Options (words may be used more than once): Trait, Gene, Genotype, Phenotype,
Recessive, Heredity, Traits, and Dominant
Example: Crossing a Tall Corn Plant (TT) and Short Corn (tt) Plant

Tall plants are dominant (T)
Parents
t
t
T
Tt
Tt
T
Tt
Tt

F1 Generation:

100__
% of offspring (Tt) are will be tall
Expected Results for Crossing Two F1 plants

Parents
T
t
T
TT
Tt
t
Tt
tt
F2 Generation:
 75% of offspring (TT or Tt) will be tall
 25% of offspring (tt) will be short
Do you expect to see a difference between your expected results and the ones you will
observe in this lab? Write an alternate and null hypothesis regarding this question.
Observed Results
1. Make a Data Table in the space below to record observations of short and tall corn
plants in the F2 generation:
2. What percent of your observed corn plants were tall? What percent were short? Show
calculations for full credit.
3. Chi Square Analysis:
# Observed (O)
Tall Corn
# Expected (E)
(O-E)
(O-E) 2
(O-E) 2/E
Short Corn
Total


-
-
x2 =
If your x2 value exceeds 3.841 you can reject your null hypothesis.
If your x2 value equals or is less than 3.841 you fail to reject your null
hypothesis.
4. Was there a significant difference between the ratio of tall to short corn plants you
expected and the ratio you actually observed? (Hint: Did you reject your null
hypothesis?)