Chapter 24 Part 1 PDF, Seeded Plants
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This document details the characteristics and adaptations of gymnosperms, including their vascular tissues, methods of reproduction, and different types of gymnosperm phyla. It also provides information on their ethnobotanical uses. The document provides an overview of the key concepts for understanding gymnosperm biology.
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Chapter 24 Seeded Plants: Gymnosperms (Part 1) Gymno= naked & seeds Adaptations needed to live in a terrestrial environment? Ways to obtain nutrients in water? ○ Stay close to water or develop vascular tissue Ways to keep water and stop desiccation? ○ Waxy cuticles on all surfaces keep water inside...
Chapter 24 Seeded Plants: Gymnosperms (Part 1) Gymno= naked & seeds Adaptations needed to live in a terrestrial environment? Ways to obtain nutrients in water? ○ Stay close to water or develop vascular tissue Ways to keep water and stop desiccation? ○ Waxy cuticles on all surfaces keep water inside Ways to get enough but not too much sunlight? ○ Develop habitat appropriate interception structure (leaves) and ways to mitigate sunburns Ways to get carbon dioxide and release oxygen? ○ Adaptive structures for gas exchange (Stomata, lenticel, etc.) Ways to structurally support the body? ○ Develop cell and body architecture that is strong enough to grow for competition of resources and withstand winds Ways to protect and spread offspring? ○ Develop embryo protection strategies ( fruit nuts eggs) The structure is provide protection and minimal nutrients until germination ○ Develop strategies for embryo dispersal Why did seeds give to our plants that spores didn't? ○ These plants still have spores they still use micro and megaspores but now what we've done is created a seed whether it is any naked seed like a gymnosperm or a vessel seed like an angiosperm. The seed is basically an immature Sporophyte That is housed in a protective shell of some sort and there is a food Reserve in that seed. Gymnosperms dominate during the Trassica~200-250 mya First seed plants are like fern-like in appearance: ○ Pteridosperms (seed ferns)- Reclassified as Gymnosperms Gymnosperms Characteristics ○ Sporophyte Dominant ○ Heterosporous; dioecious gametophyte ○ Megaphylls (Only microphyll is Lycopodiophyta) ○ Small taxa: 4 phyla w/ 73 genera and 700 species ○ Phyla Coniferophyta-Conifers Non-motile sperm Mostly evergreen Monoecious sporophyte Largest unit Has tracheids but not vessels elements Most have needle-like leaves ○ Fascicle bundle Ethnobotanical ○ Masts (telephone pole) ○ Wood ○ Turpentine ○ “Pokewood” ○ Pine needle tea- very rich in vitamin C (not enough orange juice) ○ Fuel ○ Perfume ○ Lumber ○ Crates, furniture Cycadophyta- Cycads Dioecious sporophyte Tracheids Evergreen; typically see in tropical or subtropical areas Motile (many flagella) Ethnobotanical; ○ Horticulture uses Ginkgophyta- Ginkgo Biloba (single extant species) Maidenhair fern Dioecious sporophyte Single extant species ( means still here); Ginkgo biloba Leaves; fan shaped Braching; dichotomously Deciduous Fall; bright and gold can get large Sperm; motile vestillget Odiferous seeds Tracheids Ethnobotanical ○ Horticulture ○ Urban areas (in air pollution) ○ Take extract for bring down blood pressure ○ Can eat seeds- some culture Gnetophyta- Gnetophytes Tracheid & vessel elements Dioecious sporophyte Morphologically diverse Deciduous Non-motile sperm Gnetum- Vine-like plants with broad leaves in tropics Joint Firs (Ephedra); shrubby plants of drier regions of southwestern North America Ethnobotanical ○ Drug extracts; ephedrine for respiratory problems from a chinese species ○ Weight loss ○ Horticulturally Gametophyte Stage becomes REDUCED Vascular Tissue (Xylem and Phloem) ○ Gymnosperms xylem: Tracheids (all 4 phyla) Vessel elements (Gnetophyta) ○ Wood (secondary xylem); (Secondary vascular tissue; some not all) Manoxylic: soft and loose with high parenchyma cells- Cycads Pycnoxylic: high xylem, stronger Conifers and Angiosperms Pollen (stiminate) cones (male cones; male strobili) house the microspores that grow into pollen grains (male gametophyte) that can mature and send sperm to female gametophyte Female (ovulate) cones (strobili) I produce the megaspores that will grow into the female gametophyte that produces the archegonia and ovule that will be fertilized and become a seed. Seed Plant Classification (Superdivision; Superphylum) ○ Superdivision: Spermatophyta (Tracheophyta) Phylum Coniferophyta (Pinophyta)- Conifers Phylum Ginkgophyta- Ginkgo Biloba Phylum Cycadophyta- Cycads Phylum Gnetophyta- Gnetophytes Part 2- Coniferophyta Phylum Coniferophyta- Conifers Pines (Pinus sp.- largest genus) ○ Needle- like leaves ○ Mostly Monoecious Include world’s oldest known living organisms- Bristlecone pines Image Below (left)- 3 Needles and two vascular bundle IMPORTANT Female Conifers- NC NATIVE: Bald Cypress ( Taxodium distichum ○ deciduous= looses needles in winter (bright red, orange) Longleaf Pine (Predominant) -(Pinus palustris) SUPER THICK bark can withstand fires Loblolly Pine (Pinus taeda) Eastern Red Cedar (Juniperus virginiana) Frasier Fir (abies fraseri)