Final answer:
Gregor Mendel's 1865 research on pea plants led to the discovery of how traits are inherited, introducing the concepts of dominant and recessive traits which laid the groundwork for modern genetics.
Step-by-step explanation:
In 1865, Gregor Mendel presented his groundbreaking findings on genetic inheritance using pea plants. Through meticulous cross-pollination experiments with these plants, Mendel discovered that traits are passed from parents to offspring in a predictable manner.
He identified that there are dominant and recessive traits, with dominant ones visibly manifesting in the offspring even if only one parent contributes that trait. Intriguingly, Mendel's work provided insights that helped establish the laws of inheritance even before the discovery of genes and DNA.
Mendel's experiments with nearly 30,000 pea plants revealed that physical characteristics are transmitted to subsequent generations in discreet units, later understood as genes, and do not blend as then-common theories suggested.
His findings, once overlooked by the scientific community, became the foundation for modern genetics. The terms 'dominant' and 'recessive' refer to the visibility of a trait in the offspring; for instance, when crossing purebred tall and dwarf pea plants, the tall characteristic was dominant as all offspring were tall.