A lilly from a true-breeding line with white flowers and short corollas (line A) is crossed to a lilly from a true-breeding line with black flowers and long corollas (line B). The resulting offspring, the F1, are all red-flowered, with corollas of medium length. Suppose an individual from the F1 is crossed to an individual from line A. The resulting offspring are as follows: 50% white flowers and short corollas, 50% red flowers and medium corollas. What is the term for when one locus affects two or more traits? In the scenario above, how many types of gametes can the F1 plants make?