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Unformatted text preview: connected by plasmodesmata to sieve-tube elements in phloem throughout the plant; derived from same mother cell as sieve-tube element apparently sends ATP and signal substances to the enucleate sieve-tube elements thus controlling cellular metabolism of the sieve tube elements in angiosperms Sieve cell elongated and tapering, living at maturity; primary cell wall with sieve areas; lacks a nucleus; cytoplasmn with much tubular endoplasmic reticulum in phloem throughout the plant conducts dissolved carbohydrates and other foods in gymnosperms...
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- Fall '08