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30 Cards in this Set
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Gymno ovule |
the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s) forming its outer layer(s), the nucellus (or remnant of the megasporangium), and female gametophyte (formed from haploid megaspore) in its center. |
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gymno male strobili |
pollen cone consisting of papery or membranous scales -Microsporangia in pairs towards bases of scales -structurally similar among all conifers except scale arrangement |
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gymno scale |
Bract scales: derived from modified leaf Seed scales: has two ovules that develop into seeds after fertilization |
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pollen grains |
male gametophytes of seed plants that produce gametes (Sperm cells) sporopollenin protects the gametophytes during their movement to female gamete |
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prothallial cell |
one of the cells produced by the first division of the microspore in a gymnosperm and believed to be a vestige related to the fern prothallus |
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transfusion tissue |
tissue that is found characteristically around the vascular bundles of gymnosperm leaves and consists of both living cells like those of parenchyma with walls that are not lignified and thin-walled but lignified tracheids with bordered pits. |
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hypodermis |
located below the epidermis; 1-2 layers of thick-walled cells |
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Pollen Chamber |
cavity in the micropylar end of the nucellus of the ovule of some gymnosperms in which pollen grains lodge as a result of pollination and where they develop further and germinate |
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Fascicle |
AKA cluster Short shoots with restricted growth - Contain 2 to 5 needles with scale like leaves at base |
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Polyembryony |
two or more embryos developing from a single fertilized egg |
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generative cell |
a reproductive cell, especially a cell of an angiosperm pollen grain that divides to produce two male gamete nuclei. |
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scale leaves |
a small modified leaf, especially a colorless membranous one, such as on a rhizome or forming part of a bulb. |
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needle leaves |
found in fascicles on gymnosperm twigs (bundles of 2-5 needles) |
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4 main gymnosperm phyla |
Pinophyta - Conifers Ginkgophyta - Ginko Cycadophyta - Cycads Gnetophyta - Gnetophytes |
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gymno sperm new evolutionary adaptations |
protective seed coat supply of food for embryo capable of dormancy in shitt conditions |
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where is the female gametophyte of a gymnosperm produced? |
inside an ovule that contains a nucellus
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what is the nucellus enclosed in? (gymnosperms) |
the integument *integument becomes seed coat after fertilization |
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which of the 4 types of plants (bryo, tracheo, gymno angio) does the gametophyte become dependent on sporophyte? |
gymno |
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largest genus of gymnos |
pinus (pines) dominant trees in coniferous forests of N. Hemisphere |
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modifications of Pinus |
Hypodermis Thick cuticle recessed stomata resin canals -Antiseptic, aromatic, antifungal, insect deterrent Fungal symbiosis |
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pine wood consists entirely of? |
tracheids |
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Pine reproduction |
heterosporous microsporocytes produce 4 haploid microspores -each microspore undergoes mitosis and forms 4 celled pollen grain -2 prothallial cells -1 generative cell -1 tube cell |
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seed cone development (year 1) |
Pollen grain sticks to ooze from micropyle grain produces pollen tube; grows through nucellus -2 sperms in pollen tube Megaspore develops |
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seed cone development (year 2) |
Female gametophyte and archegonium mature pollen tube reaches archegonium one sperm unites with egg -zygote formed - other sperm degenerates Emryo nourished by female gametophyte Integument becomes seed coat |
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modifications: Yew (Taxus) and California nutmeg (Torreya) |
single ovule at shoot tip -partially surrounded by fleshy cuplike aril |
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Modifications: Podocarpus |
Fleshy, coated seed with large appendage at base |
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Modifications: Juniper |
seed cones fleshy |
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Gingko Biloba (maidenhair tree) |
only exists in cultivation
life cycle similar to pines seeds enclosed in fleshy seed coat with nauseating odor |
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Cycadophyta (cycads) |
slow-growing; tropics/subtropics Tall unbranched trunks crown of large pinnately divided leaves central strobili |
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gnetophyta |
unique in gymno's because it has vessels in xylem Ex. Joint firs (Ephedra): Shrubby plants of drier regions of S.W. Na Gnetum: Vinelike plant with broad leaves Welwitschia: 1spp. confined to SW African deserts |
