1. Lesson 40 Mendel and Peas

2. Activator Which trait is dominant? Attached or detached earlobe
Cleft chin or Smooth chin
Second toe longest or Big toe longest
Migraine or no migraine
Six Fingers or Five fingers

3. Mendel and His Peas
Mendel crossed flowers that were pure bred for each characteristic.
He crossed a purple (PP) flowered plant with a white (pp) flowered plant. (Parent Generation)

4. Mendel and his Peas (Pp) (Pp) (Pp)
Purple Parent (PP)
  (Pp)   
(Pp)
   (Pp)
The first generation (F1) of plants all had purple flowers.
Where did the white color go??
White Parent (pp)

5. Peas (PP) (Pp) (Pp) (pp)
Purple Parent (Pp)   
(PP)
  (Pp)
  (Pp)
  (pp)
Mendel took two of his first generation (F1 x F1) purple flowered plants and crossed them together.
In the second generation (F2) he had 3 purple flowered plants, and 1 white flowered plant.
Purple Parent (Pp)

6. Peas
Mendel noticed in the first generation, all of the white flowers seemed to disappear.
He called this a recessive trait.
The white color faded into the background at first.
It showed up in the next generation when he pollinated the flowers.

7. Peas
The color (purple) that seemed to mask over the recessive color was named the dominant trait.
Purple: Dominant (Big P)
White: Recessive (little p) PP Pp pp

8. Conclusion
Mendel was responsible for figuring out that each plant carried two sets of instructions for each characteristic (one from “mom” and one from “dad”).

9. Brain Break