Given a scientific passage and an answer, generate a question for the given answer.

Q: Passage: Molecular compounds are inorganic compounds that take the form of discrete molecules . Examples include such familiar substance as water (H 2 O) and carbon dioxide (CO 2 ). These compounds are very different from ionic compounds like sodium chloride (NaCl). Ionic compounds are formed when metal atoms lose one or more of their electrons to nonmetal atoms. The resulting cations and anions are electrostatically attracted to each other. Answer: molecular compounds

A: What are inorganic compounds that take the form of discrete molecules called?
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Q: Passage: Oxygen is needed to make ozone. Ozone is a molecule made of three oxygen ions. Ozone in the upper atmosphere blocks harmful solar radiation from reaching the surface. Without oxygen, life on Earth would have been very simple. Answer: three

A: How many oxygen ions make up an ozone molecule?
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Q: Passage: They have lots of mitochondria. Mitochondria are called the power plants of the cell, as these organelles are where most of the cell's energy is produced. Cells that need lots of energy have lots of mitochondria. Answer: mitochondria

A:
What organelles are known as the "power plants" of the cell?
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