primary sieve

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• angiosperm — /an jee euh sperrm /, n. Bot. a plant having its seeds enclosed in an ovary; a flowering plant. Cf. gymnosperm. [ANGIO + SPERM] * * * ▪ plant Introduction       any member of the more than 300,000 species of flowering plants (division Anthophyta) …   Universalium

• Tissue (biology) — This article is about biological tissue. For other uses, see Tissue. Cross section of sclerenchyma fibers in plant ground tissue …   Wikipedia

• petroleum refining — Introduction  conversion of crude oil into useful products. History Distillation of kerosene and naphtha       The refining of crude petroleum owes its origin to the successful drilling of the first oil well in Titusville, Pa., in 1859. Prior to… …   Universalium

• Plant cell — Plant cells are eukaryotic cells that differ in several key respects from the cells of other eukaryotic organisms. Their distinctive features include: * A large central vacuole, a sap filled volume enclosed by a membrane known as the tonoplast JA …   Wikipedia

• Phloem — Cross section of a flax plant stem: 1. Pith, 2. Protoxylem, 3. Xylem I, 4. Phloem I, 5. Sclerenchyma (bast fibre), 6. Cortex, 7. Epidermis In vascular plants, phloem is the living tissue that carries organic …   Wikipedia

• lower vascular plant — ▪ biology Introduction formerly  pteridophyte,  also called  vascular cryptogam,         any of the spore bearing vascular plants, including the ferns, club mosses, spike mosses, quillworts, horsetails, and whisk ferns. Once considered of the… …   Universalium

• Multiplication algorithm — A multiplication algorithm is an algorithm (or method) to multiply two numbers. Depending on the size of the numbers, different algorithms are in use. Efficient multiplication algorithms have existed since the advent of the decimal system.… …   Wikipedia

• phloem — /floh em/, n. the part of a vascular bundle consisting of sieve tubes, companion cells, parenchyma, and fibers and forming the food conducting tissue of a plant. [ < G (1858), irreg. < Gk phló(os) bark (var. of PHLOIÓS) + ema deverbal n. ending]… …   Universalium

• wood — wood1 woodless, adj. /wood/, n. 1. the hard, fibrous substance composing most of the stem and branches of a tree or shrub, and lying beneath the bark; the xylem. 2. the trunks or main stems of trees as suitable for architectural and other… …   Universalium

• Wood — /wood/, n. 1. Grant, 1892 1942, U.S. painter. 2. Leonard, 1860 1927, U.S. military doctor and political administrator. * * * I Hard, fibrous material formed by the accumulation of secondary xylem produced by the vascular cambium. It is the… …   Universalium

• Prime number — Prime redirects here. For other uses, see Prime (disambiguation). A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is… …   Wikipedia