You will be given a definition of a task first, then some input of the task.
Given a scientific passage and an answer, generate a question for the given answer.

Passage: An ecosystem is a group of living things and their environment. The word ecosystem is short for "ecological system. " Like any system, an ecosystem is a group of parts that work together. You can see examples of ecosystems in Figure below . The forest pictured is a big ecosystem. Besides trees, what living things do you think are part of the forest ecosystem? The dead tree stump in the same forest is a small ecosystem. It includes plants, mosses, and fungi. It also includes insects and worms. Answer: ecosystem
Output:
A group of living things and their environment is called what?