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单词 cotyledon
释义

cotyledon


cotyledonbean seed germinating

cot·y·le·don

C0679800 (kŏt′l-ēd′n)n.1. Botany A leaf of the embryo of a seed plant, which upon germination either remains in the seed or emerges, enlarges, and becomes green. Also called seed leaf.2. Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.
[Latin cotylēdōn, navelwort, from Greek kotulēdōn, from kotulē, hollow object.]
cot′y·le′don·ar′y (-ēd′n-ĕr′ē), cot′y·le′don·al (-ēd′n-əl), cot′y·le′do·nous (-ēd′n-əs) adj.

cotyledon

(ˌkɒtɪˈliːdən) n1. (Botany) a simple embryonic leaf in seed-bearing plants, which, in some species, forms the first green leaf after germination2. (Zoology) a tuft of villi on the mammalian placenta[C16: from Latin: a plant, navelwort, from Greek kotulēdōn, from kotulē cup, hollow] ˌcotyˈledonal adj ˌcotyˈledonary adj ˌcotyˈledonous, ˌcotyˈledoˌnoid adj

cot•y•le•don

(ˌkɒt lˈid n)

n. the primary or rudimentary leaf of the embryo of seed plants. [1535–45; < Latin: navelwort < Greek kotylēdṓn literally, a cuplike hollow, derivative of kotýlē cup] cot`y•le′don•al, cot`y•le′don•ar`y (-ˌɛr i) cot`y•le′don•ous, adj.

cot·y·le·don

(kŏt′l-ēd′n) A leaf of the embryo of a seed-bearing plant. Most cotyledons emerge, enlarge, and become green after the seed has germinated. Cotyledons either store food for the growing embryo or absorb food that has been stored in the endosperm for eventual distribution to the growing parts of the embryo. Also called seed leaf. See more at dicotyledon, monocotyledon.

cotyledon

A seed leaf that provides food for an embryo plant.
Thesaurus
Noun1.cotyledon - embryonic leaf in seed-bearing plantscotyledon - embryonic leaf in seed-bearing plantsseed leafcataphyll - a reduced or scarcely developed leaf at the start of a plant's life (i.e., cotyledons) or in the early stages of leaf development
Translations
κοτυληδόναcotiledone

cotyledon


cotyledon

(kŏt'əlēd`ən), in botany, a leaf of the embryo of a seedseed,
fertilized and ripened ovule, consisting of the plant embryo, varying amounts of stored food material, and a protective outer seed coat. Seeds are frequently confused with the fruit enclosing them in flowering plants, especially in grains and nuts.
..... Click the link for more information. . The embryos of flowering plants, or angiospermsangiosperm
, term denoting seed plants in which the ovules, or young seeds, are enclosed within the ovary (that part of the pistil specialized for seed production), in contrast to the gymnosperms, in which the seeds are not enclosed within an ovary.
..... Click the link for more information. , usually have either one cotyledon (the monocots) or two (the dicots). Seeds of gymnosperms, such as pines, may have numerous cotyledons. In some seeds the cotyledons are flat and leaflike; in others, such as the bean, the cotyledons store the seed's food reserve for germination and are fleshy. In most plants the cotyledons emerge above the soil with the seedling as it grows. They differ in form from the true leaves.

Cotyledon

 

one of the first leaves of a plant. The cotyledons form in the seed on the not yet differentiated body of the developing embryo. They often differ sharply in shape, internal structure, and, sometimes, function from subsequent leaves that arise on the growing point of the shoot. Gymnospermous plants have two to 15 cotyledons, dicotyledonous plants two cotyledons, and most monocotyledonous plants one cotyledon. When there is aboveground sprouting of dicotyledon seeds (for example, beans), green cotyledons emerge at the soil surface and for some time perform the functions of green leaves. In peas, oak, walnut, and a number of other plants the cotyledons upon sprouting remain in the seed and die after consumption of nutrient reserves. During the sprouting of many monocotyledons, the sheath portion of the cotyledon emerges from the seed, but the apex remains for some time in the endosperm, functioning as an organ of absorption. The same function is performed by the scutellum that remains in the seed of cereal grains; many botanists consider the scutellum to be a cotyledon.

cotyledon

[‚käd·əl′ēd·ən] (botany) The first leaf of the embryo of seed plants.

cotyledon

1. Botany a simple embryonic leaf in seed-bearing plants, which, in some species, forms the first green leaf after germination 2. Anatomy a tuft of villi on the mammalian placenta

cotyledon


cotyledon

 [kot″ĭ-le´don] 1. any subdivision of the uterine surface of the placenta.2. irregular convex areas on the chorionic surface of the placenta, consisting of two or more stem villi and their many branch villi; by the end of the fourth month the decidua basalis is almost entirely replaced by the cotyledons.

cot·y·le·don

(kot'i-lē'don), 1. 2. In plants, a seed leaf, the first leaf to grow from a seed. 3. A placental unit. [G. kotylēdon, any cup-shaped hollow]

cotyledon

(kŏt′l-ēd′n)n.1. Botany A leaf of the embryo of a seed plant, which upon germination either remains in the seed or emerges, enlarges, and becomes green. Also called seed leaf.2. Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.
cot′y·le′don·ar′y (-ēd′n-ĕr′ē), cot′y·le′don·al (-ēd′n-əl)(-ēd′n-əs), cot′y·le′do·nous (-ēd′n-əs) adj.

cot·y·le·don

(kot'i-lē'dŏn) 1. In plants, a seed leaf, the first leaf to grow from a seed. 2. Irregular convex area of the fetal part of the placenta composed of stem villi. [G. kotylēdon, any cup-shaped hollow]

cotyledon

  1. a part of the plant embryo in the form of a specialized seed leaf that can be thin and papery, as in the castor oil plant, or can act as a storage organ, as in the broad bean, absorbing food from the endosperm. Sometimes it also functions as a leaf after EPIGEAL germination, as in the runner bean. Some ANGIOSPERMS have one cotyledon per seed (MONOCOTYLEDONS) while others have two (DICOTYLEDONS).
  2. a part of the mammalian placenta on which a tuft of villi occurs, particularly in ruminants.

cotyledon


  • noun

Synonyms for cotyledon

noun embryonic leaf in seed-bearing plants

Synonyms

  • seed leaf

Related Words

  • cataphyll
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更新时间：2025/1/29 7:49:58