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X chromosome

(Science: genetics) A sex chromosome. In mammals paired in females (XX), in amphibia paired in males. The sex chromosome that is present in both sexes: singly in males and doubly in females; human females normally have two X chromosomes.One of the sex chromosomes found in both sexes. The X chromosome in males can express many dominant sex-linked traits because the shorter opposing Y-chromosome has no homologous genes to challenge the dominance of some genes on the Y chromosome....

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/ˈzɪərɪk,ˈzɛ-/ Adjective 1. (of an environment or habitat) containing little moisture; very dry. (Google Dictionary) 2. Said of an organism adapted to live in a very dry habitat. ( 3. Characterized by, relating to, or requiring only a small amount of moisture. ( Word origin: From xero- (before vowels, xer-, word-forming element meaning “dry,” from Greek xero-, comb. form of xeros...

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Noun 1. Plant adapted for life with a limited supply of water; compare hydrophyte and mesophyte. ( 2. An extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Water activity (aw) is a measure of the amount of water within a substrate an organism can use to support sexual growth. Xerophiles are often said to be “xerotolerant”, meaning tolerant of dry conditions. They can survive in environments with water activity below 0.8. Endoliths and halophiles are often xerotolerant. (   Word origin: from Greek xēros /ˈzɪroʊs/, meaning “dry”, and philos, meaning...

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/ˈzɪərə(ʊ)fʌɪt,ˈzɛ-/ Noun, plural xerophytes 1. A species of plant that has adapted to survive in an environment with little water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic. ( 2. A desert plant. ( Word origin: From xero-, a word-forming element meaning “dry,” from Greek xero-, comb. form of xeros “dry”; + Greek phyton “a...

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/ˈzɪfɔɪd/ Adjective 1. Shaped like a sword, ensiform. ( 2. Of, or relating to the xiphisternum. ( Word origin: From xiphias “swordfish” + –oid word-forming element meaning “like, like that of, thing like a...

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