Hooper/Life Science 2014
Dihybrid Cross Extra Credit
Dihybrid cross: a cross between two individuals that differ in two traits of particular interest.
Students will create an original and unique dihybrid cross.
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The genotypes and phenotypes of each parent must be provided (2 points).
An accurate dihybrid cross Punnett Square (16 boxes) must be completed (2 points).
The phenotypic percentages of the offspring must be provided (2 points).
Students may earn a maximum of six extra credit points.
Notes:
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The Cells and Heredity textbook pg. 79 and the handout featuring the traits investigated
by Gregor Mendel in pea plants can be used to choose traits for the dihybrid cross.
No two students may have the same dihybrid cross.
Example:
The cross of two pea plants that each produce round, yellow peas.
RrYy x RrYy
Phenotypic Percentages of
Offspring
Round, yellow
56.25%
Round, green
18.75%
Wrinkled, yellow
18.75%
Wrinkled, green
6.25%
Image source:
http://www2.estrellamountain.edu/faculty/far
abee/biobk/dihyb2.gif