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

Q: Passage: All living things are capable of reproduction, the process by which living things give rise to offspring. Answer: reproduction

A: All living things are capable of what process whereby living things give rise to offspring?
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Q: Passage: The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Answer: protons and neutrons

A: What makes up the mass number of an atom?
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Q: Passage: The arthropod exoskeleton consists of several layers of cuticle. The exoskeleton prevents water loss and gives support and protection. It also acts as a counterforce for the contraction of muscles. The exoskeleton doesn't grow as the animal grows. Therefore, it must be shed and replaced with a new one periodically through life. This is called molting . Answer: exoskeleton

A:
What part of an animal helps to prevent water loss and gives support and protection?
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