1. Mendel and his Peas

2. Why Don’t You Look Like a Rhinoceros?
Heredity – passing of traits from parent to offspring

3. Who was Gregor Mendel? Born in 1822 Austrian monk
Studied how traits are passed from parent to offspring in the monastery garden

4. Unraveling the Mystery
Mendel studied pea plants
WHY?
Easy to grow
Have many traits
Pea plants can self-pollinate
– this means the plant has both MALE and FEMALE reproductive parts

5. Self Pollinating
During pollination, pollen from the anthers (male) is transferred to the stigma (female)

6. How many different “forms” of eye color exist?
Peas Be My Ponder
Mendel chose to study only one characteristic at a time such as
- height OR pea color
Tall/Short Green/Yellow
And he chose plants that had two forms for each of the characteristics studied
How many different “forms” of eye color exist?

7. Pea Plant Traits Characteristics:
Use Figure 4 (pg 110) in your textbook to list the 7 characteristics of pea plants and their two forms – think, pair, share!

8. Pea Traits

9. True Breeding Plants
A true bred parent will ALWAYS produce offspring with the same trait
Examples …
A true bred purple flower will produce ? flowers
A true bred yellow seed will produce ? seeds

10. MENDEL’s 1st Experiment
Mendel crossed two true bred plants with different forms of the same trait
Wrinkled seed plant X Round seed plant

11. MEDEL’S 1ST EXPERIMENT
When Mendel crossed round seed plants X wrinkled seed plants, the new plant had ALL ROUND seeds
The offspring from this cross are known
as the First generation or F1

12. MENDEL’S 1ST EXPERIMENT
For each cross, one trait always appeared and the other seemed to vanish in F1
Dominant – trait that appears/stronger
Recessive – trait that vanishes/hidden
What is the dominant trait?
What is the recessive trait?

13. MENDEL’S 2nd EXPERIMENT
Mendel allowed first generation (F1) from each cross to self-pollinate
 Round seeds X Round seeds
When the F1 generation self-pollinated, the wrinkled (recessive) reappeared in the Second generation (F2)!

14. MENDEL’S RESULTS
MENDEL’S RESULTS: In the 2ndgeneration, the RECESSIVE trait showed up again but NOT as often as the DOMINANT Can you determine the ratio of D to R? __:__

15. MENDEL’S EXPERIMENTS
Use Figure 6 (p. 109) to explain Mendel’s First and Second Experiments:

16. MENDEL’S EXPERIMENTS