TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: If two populations do not mate and produce fertile offspring, separate species result.

SOLUTION: If two populations do not mate and produce fertile offspring, what results?

PROBLEM: Seedless and seed are the two divisions of vascular plants.

SOLUTION: What are the two divisions of vascular plants?

PROBLEM: The mantle layer of earth is located just below the crust.

SOLUTION:
What layer of Earth is located just below the crust?