The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the age of the dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition from the pollen and are sheltered from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen (containing the flagellated sperm) to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Which feature of cycads distinguishes them from most other gymnosperms?
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For each of the formulas, classify the formula as either an empirical formula, a molecular formula, or both. nahco3 empirical molecular both
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The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were do...
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