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

Q: Passage: Potential energy is energy that is stored in a person or object. Answer: potential energy

A: Energy that is stored in a person or object is called?
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Q: Passage: Sensory organs such as the eyes contain cells called sensory receptors that respond to particular sensory stimuli. Answer: sensory receptors

A: Sensory organs that respond to particular sensory stimuli contain cells called what?
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Q: Passage: Some of the oldest evidence of evolution comes from embryology , the study of how organisms develop. An embryo is an animal or plant in its earliest stages of development. This means looking at a plant or animal before it is born or hatched. Centuries ago, people recognized that the embryos of many different species have similar appearances. The embryos of some species are even difficult to tell apart. Many of these animals do not differ much in appearance until they develop further. Answer: embryology

A:
The study of how organisms develop is known as?
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