Given a scientific passage and an answer, generate a question for the given answer.

Example input: Passage: A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:. Answer: nucleotides.
Example output: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Example explanation: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.
Q: Passage: Epiphytic roots enable a plant to grow on another plant. For example, the epiphytic roots of orchids develop a spongy tissue to absorb moisture. The banyan tree (Ficus sp. ) begins as an epiphyte, germinating in the branches of a host tree; aerial roots develop from the branches and eventually reach the ground, providing additional support (Figure 30.20). In screwpine (Pandanus sp. ), a palm-like tree that grows in sandy tropical soils, aboveground prop roots develop from the nodes to provide additional support. Answer: epiphytic
A:
What type of roots enable a plant to grow on another plant?