In an attempt to produce a coffee plant that would yield beans containing no caffeine. the synthesis of a substance known to be integral to the initial stages of caffeine production was blocked either in the beans, in the leaves, or both. For those plants in which synthesis of the substance was blocked only in the leaves. the resulting beans contained no caffeine.
Any of the following. if true, would provide the basis for an explanation of the observed results
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AIn coffee plants, the substance is synthesized only in the leaves and then moves to the beans, where the initial stages of caffeine production take place.
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B In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
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CIn coffee plants. the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.
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D In coffee plants. caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
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ECaffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
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正确答案: C