In many organisms, it is possible to see the chiasmata that form during meiosis I. Suppose that a chromosome has two easily observed physical landmarks such as a knob at one end and a constriction that forms nearby. When the gametes are examined cytologically, 10% of them have a chiasma between the knob and the constriction. What is the approximate map distance between the knob and the constriction? (Hint: The answer is not 10 map units.).