Gregor Mendel
The Paternity Test of today, traces its conceptual roots back to Gregor Mendel and his study of dominant and recessive traits in pea plants. In 1863, Mendel cultivated and tested more than 29,000 pea plants, looking specifically at characteristics like flower size, color and shape. From this study, he developed what later became known as Mendel’s law of inheritance.
Mendel discovered that, for some traits, one out of four pea plants were pure-recessive, two were hybrids, and one was pure-dominant. The British biologist R.C. Punnett later developed an inheritance square showing how dominant and recessive traits work together.
Imagine hybrid parent plants having two alleles, or genes. A parent will pass only one of its genes on to a child plant. These genes, or alleles, control the flower color for the child plant. The DNA of the hybrid parent plants includes one gene for purple (capital 'R' - the dominant allele) and one gene for white (lowercase 'r' - the recessive allele).
A child plant, with two hybrid parents, could possibly have the following genes, or alleles:
| Hybrid Parent Plant 2 | |||
| ALLELES (GENES) |
R | r | |
| Hybrid Parent Plant 1 | R | RR (purple pure-dominant) |
Rr (purple hybrid) |
| r | rR (purple hybrid) |
rr (white pure-recessive) |
|
Plants with one or more dominant alleles showed the dominant trait (purple-colored flowers) while plants with only recessive alleles show the recessive traits (white-colored flowers).
