Theories are educated guests that are tested by experiments
Answer:
Digestion
Explanation:
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream
Natural selection is when certain environmental qualities cause a species to evolve in order to survive in the environment. Natural selection is a specific part of that, when some of the variations of the species die off because they can't survive, then the ones who survive live to create more living babies with the qualities that allow them to survive in the environment.
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