Definition: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Roots are important organs in all vascular plants. Most vascular plants have two types of roots: primary roots that grow downward and secondary roots that branch out to the side. Together, all the roots of a plant make up a root system . Answer: downward
Output:
In vascular plants, do primary roots grow downward or to the side?