Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: As plant cells grow, they also become specialized into different cell types. Once cells become specialized, they can no longer divide. So how do plants grow after that? The key to continued growth is meristem. Meristem is a type of plant tissue consisting of undifferentiated cells that can continue to divide. Answer: divide
Once a plant cell becomes specialized, what can they no longer do?