Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: In some species, the same individual produces both sperm and eggs. But worms mate to exchange sperm, rather than self-fertilizing their own eggs. Fertilized eggs are deposited in a mucous cocoon. Offspring emerge from the cocoon looking like small adults. They grow to adult size without going through a larval stage. Answer: larval
Solution:
Worms grow to adult size without going through what stage?