Table 1 Mendel's novel observations summarised. Mendel demonstrated that crossing parental plants bearing alternative forms (A) and (a) of any one of seven traits generated a F1 population of plants (not shown) all of which were hybrids (Aa). Each of these F1 hybrid plants displayed only one of the two alternative parental traits, defined as the dominating trait (A). When these F1 hybrid plants were allowed to self-fertilise, the ratio of dominant to recessive traits in the F2 population was always close to 3:1.
Pairs of parental plants | Their F2 progeny | ||
|---|---|---|---|
Dominant traits (A) | Recessive traits (a) | Number of F2 plants examined | Dominant:recessive trait ratio in the F2 population |
Green pods | Yellow pods | 580 | 2.82:1 |
Axial flowers | Terminal flowers | 858 | 3.14:1 |
Red flowers | White flowers | 929 | 3.15:1 |
Long stems | Short stems | 1064 | 2.84:1 |
Inflated pods | Constricted pods | 1181 | 2.95:1 |
Round seeds | Wrinkled seeds | 7324 | 2.96:1 |
Yellow seeds | Green seeds | 8023 | 3.01:1 |