Question 8
A grower has a plantation of healthy papaw trees that produces no fruit at all. What is the most likely reason?
The right answer is the one marked above.
Papaw is dioecious, so the trees may all be of one sex. Staminate and pistillate flowers arise on separate plants, so a plantation of only male trees will never fruit — and neither will one of only female trees.
Papaw is the standing example of a dioecious plant, alongside Vallisneria, so it is not bisexual and not monoecious. Cross-species pollination is not how any of this works, and parthenocarpy is a different phenomenon entirely.