From Seed to Seed:
Plant Science for K-8 Educators

Mendel's famous peas

Before we get into diagrams of genes and chromosomes, let's travel back to the time before powerful microscopes-before scientists could actually view the genetic material within a nucleus.

The pioneer in the study of genetics was Gregor Mendel (1822-1884), an Austrian monk. Mendel studied the cross-breeding of common peas in the monastery's garden, and in 1866 published the results of his now-famous experiments. Mendel's creative and innovative interpretation of his data is considered to be one of the greatest intellectual achievements by an individual in the history of science! Mendelian genetics ultimately revolutionized the science of biology and provided support for Darwin's theories of natural selection.

Mendel worked on his theories of inheritance long before there was any evidence of the existence of chromosomes and genes. For 10 years he studied certain traits of the common pea plant, Pisum sativum.

Mendel studied seven traits in pea plants, each of which had two different, distinct expressions:

• seed color (yellow or green).
• seed coat (round or wrinkled).
• flower color (red or white).
• pod shape (inflated or constricted).
• stem length (long or short).
• flower position (axial or terminal).
• pod color (green or yellow).