Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
--------
Question: Population is an important level of organization in ecology and the unit of microevolution.

Answer: What is an important level of organization in ecology and the unit of microevolution?


Question: Some meteorites are made of iron and nickel and are thought to be very similar to the core of the earth.

Answer: Some meteorites are made of iron and nickel and are thought to be very similar to what part of the earth?


Question: Optics explains the behavior of visible light and electromagnetic waves.

Answer:
What type of physics explains the behavior of visible light and electromagnetic waves?