instruction:
Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
question:
Question: How high or low a sound seems is associated with what property of the sound? Answer: pitch
answer:
How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves.

question:
Question: What is a pair of valence electrons in a bonded atom that does not participate in bonding called? Answer: lone pair
answer:
A pair of valence electrons in a bonded atom that does not participate in bonding is called a lone pair. Lone pair electrons contribute to molecular shape.

question:
Question: What is an important level of organization in ecology and the unit of microevolution? Answer: population
answer:
The population is an important level of organization in ecology. It is also the unit of microevolution.