EXPERIMENTAL SET UP / BACKGROUND INFORMATION 

In CGS #3 students focused on the flowers of the Arabidopsis plant.  The plant can have three different flower colors, red, white and pink. 

Because there are three traits, there will be more than three possible crosses (unlike CGS 1 and 2). The possible crosses are:

1. White and White

2. White and Red

3. White and Pink 

4. Red and Red

5. Red and Pink 

6. Pink and Pink

Initially students were asked to do cross 2 (white and red) and cross 6 (pink and pink).  Later in CGS #3, students will do some of the other crosses to test the models that they develop to explain crosses 2 and 6. 

OBSERVATIONS / DATA 

• Cross 2 (red and white) outcomes. 

  • All offspring are pink 

• Cross 6 (pink and pink) outcomes

  • 2/4 of offspring plants are pink

  • 1/4 of offspring  plants are red

  • 1/4 of offspring plants are white 

• Again we are noticing similar patterns of inheritance, all outcomes are again occuring in fourths. 

• This time however, students observed that the red x white cross produces a blended outcome (pink) 

If a red flowered plant is crossed with a white flowered plant, the only outcome / all of the offspring will be pink.  Since pink is a blend of red and white, this must mean that the pink plants got genetic information from their red parent and their white parent.  This also means that the pink plant must have two pieces of genetic information that cause it to look the way that it does.