GREGOR MENDEL NOTES....

Gregor Mendel measured seven pea characteristics:

• Color and smoothness of the seeds - grey and round or white and wrinkled
• Color of the cotyledons (part of the embryo within the seed) - yellow or green
• Color of the flowers - white or violet
• Shape of the pods - full or constricted
• Color of unripe pods - yellow or green
• Position of flowers and pods on the stems
• Height of the plants - short or tall

In his 1st experiment, Mendel cross-pollinated smooth yellow pea plants with wrinkly green peas. Every single pea in the first generation experiment was as yellow and as round as was the yellow, round parent. Somehow, yellow completely dominated green and round dominated wrinkly.
Mendel learned from this that there are two kinds of traits - dominant and recessive. In this case, the dominant traits are the yellow color and the round shape since they show up at the expense of the green color and the wrinkly shape. He also learned that the inheritance of each trait is determined by genes.

Now he went on with his experiment and planted seeds from the all-yellow, all-round crop, achieved from the parent generation, and self-pollinated the grown up plants. The results led to some surprises. Most of the second generation of peas were yellow and smooth, but some were green or wrinkly. Mendel repeated his experiment many times 2nd generation consistently had a 3:1 ratio of yellow to green and round to wrinkly.