When Mendel crossed plants that were purebred purple-flowered with plants that were purebred white-flowered, the resulting offspring all had purple flowers. When allowed to self-pollinate, this F generation gave rise to white-flowered plants as well as purple. As a result, Mendel determined that individual traits are:_________.
a. inherited as discrete units.
b. diluted in offspring
c. merged with successive generations.
d. lost in the pollination process.