Presentation on theme: "Plant organs and tissues"— Presentation transcript:
1 Plant organs and tissues Kingdom Plantae: more than 400,000 different kinds of plants
2 Classification Cotyledons- seed leaves in their embryos monocots- single seed leaf, one group of plantsdicots- two seed leaves, another group of plants that are divided furtherAn easier way to classify is by the:1. number of seed leaves,2. the strength and composition of their stems, and3. the number of growing seasons they live.
6 Plant Life CycleA sporophyte produces haploid spores through meiosis.These spores grow into multi-cellular structures called gametophytesEach gametophyte produces reproductive cells called gametes-sperm and egg cellsDuring fertilization, a sperm and egg fuse with each other, producing a diploid zygote.The Zygote develop into a new sporophyte, and the cycle begins again.Alternation of generation between haploid and diploid phases.Diploid (2N) phase is known as the sporophyte (spore-producing plant).Haploid (N) phase is known as the gametophyte (gamete-producing plant)
9 Mosses, liverworts, and hornworts BryophytesMosses, liverworts, and hornwortsLack specialized tissues for the transport of water“nonvascular plants”mosseshornwortsliverworts
10 *Vascular Tissue: tissue that transports water and nutrients in some plants TracheophytesSeedless VascularVascular plantsSeedless plants such as ferns and both flowering and nonflowering seed plantsContain specialized tissues that transport water and nutrients =tracheidsAllows growthto large sizesFernshorsetailsClub mosses
11 Vascular Tissue Two main types of vascular tissue: forms the transport system among the roots, stems, and leaves of vascular plants.Two main types of vascular tissue:Xylem- moves water and nutrients from the ground upward in the plant.Phloem- carries food made in a plant’s leaves down to other plant parts.Roots, stems, and leaves are plant organsBryophytes do not have roots, stems, or leaves. They absorb substances directly from their surroundings.
13 Rootsanchor and support the plant, absorb water and dissolved nutrients from the soil, and store food and water.TAPROOTSFIBROUS ROOTSSingle large root that grows deep into the soil.As the root grows deeper, other smaller roots branch from the main rootdandelion, carrots, and beetsDICOTSDoes NOT have a single main rootmany small, shallow roots branch out from the base of the plantgrassMONOCOTS
15 Stems hard, rigid stems woody stem of a tree is its trunk transport materials between a plant’s roots and its leaves and flowerssupport the leaves and flowerssome plants the stems store food and water (potato).WOODY PLANTSHERBACEOUS PLANTSplants that develop into trees and shrubshard, rigid stemswoody stem of a tree is its trunklive for many yearsgrasses and many garden plantsgreen, flexible stemssmallerhave shorter life spans
17 Leavesmain organs that carry out photosynthesis in most vascular plantsStomata (stoma: singular)- small openings on their undersidescarbon dioxide and oxygen are exchanged between the plant and the air through the stomatawater may also enter and exit a leaf through the stomataGuard Cells- tiny structures, control the size of the stomatahelp control the movement of materials into and out of the plant.
21 Petiole- tubelike structure that attaches a leaf to its stem Similar structures that all leaves share:Blade- is the broad, flat part of the leaf. Absorbs sunlight needed for photosynthesis.Veins- running throughout the blade, tubelike structures that transport water in the leafPetiole- tubelike structure that attaches a leaf to its stem
22 Organs of Seed Plants Anchor and support the plant, RootsStemsAnchor and support the plant,absorb water and dissolved nutrients from the soil,and store food and waterTap roots and fibrous rootsTransport materials between a plant’s roots and its leaves and flowers.Support the leaves and flowersIn some plants, it stores food and waterWoody plants and herbaceous plantsLeavesMain organ that carry out photosynthesisPetiole, blade, veins are similar structures in all leavesMonocots and dicots
23 SeedsPlant embryo and a food supply, encased in a protective covering.Unlike mosses and ferns, gametes of seed plants do not need standing water for fertilization.Adaptations that allow for reproduction without standing water:Reproductive process that takes place in cones or flowers.Transfer sperm by pollinationProtection of embryos in seedsConesVs.Flowers
24 Gymnosperms Conifers- plants that form seeds in cones pines, cedar, firs, and juniper treesthin, needle-shaped leaves that help prevent water lossthis adaptation allows conifers to live in places that are dry or cold for part of the yearVenus flytrap is a plant with a leaf adaptation that when a insect touches a receptor, the leaf shuts and the insect becomes trapped.
25 ConesReproduction in conifers takes place in cones, which are produced by a mature sporophyte plant.produce two types of cones: pollen (male) and seed (females) conesSeed cones are much larger and contain ovules near the base of each scale.
26 Flowers are leaves that have been modified for sexual reproduction. angiospermsFlowers are leaves that have been modified for sexual reproduction.a seed plant that produces seeds enclosed in fruitsthe fruit develops inside the flowersFlower- reproductive structure of an angiospermattract birds and insects that help the plant reproducepetals surround its reproductive partsStamen- male reproductive partPistil- female reproductive partpistil contains the ovary, which produces the female sex cells and then protects the seed as they develop
30 Pathway to making a baby flower: Pollen (male sex cell) must be transferred from the stamen of a flower to the stigma on the pistilTransferred by the wind, or by animalsAnimals that transfer pollen are called pollinatorsThe transfer of pollen from the stamen to a pistil is called pollination.If pollen lands on the tip of the pistil of a similar flower, the pollen can fertilize that flowerSperm in the pollen travels through a tube to reach the eggs in the ovaryFertilization occurs when the sperm and egg cells uniteAfter fertilization, one or more seeds develop in the ovaryFinally, the ovary develops into a protective fruit
32 Flowers and fruitsAttract animals such as bees, moths, or hummingbirdsDrawn by color, scent, or even shape of the flower—carry pollen with them as they leaveThey go from flower to flower, carrying pollen as they go, which is much more efficient than the wind pollination of most gymnosperms.After pollination, ovaries develop into a fruitfruit- structure containing one or more matured ovariesthe wall of the fruit help disperse the seeds inside itanimals eat the fruit, and as the seeds travel through the digestive system, it develops and by the time it exits the animal may be miles away.