Plant Parts Plant Organs – Flowers, Leaves, Stems, Roots. What are organs? a group of tissues What are tissues? a group of specialized cells http://www.puc.edu/Faculty/Gilbert_Muth/art0061.jpg http://pubs.caes.uga.edu/caespubs/pubcd/B1252-graphics/B1252-3.jpg http://www.phschool.com/science/biology_place/biocoach/images/plants/plant.gif

Plant Tissues Plant tissues – Ground tissue – food storage Vascular tissue – delivers water and solutes Dermal tissue – protects exposed surfaces New grow takes place at meristems: Apical meristems – ends of shoots and roots where plant is lengthening. Lateral meristems – where plant increases in thickness, in stems and roots.

Monocot vs. Dicot Same tissues, organized in different ways. Cotyledons are leaflike strucutres called seed leaves which form in the seed as part of the plant embryo.

Monocot http://www.sproutpeople.com/kids/images/seed.dicot.monocot.gif http://intranet.canacad.ac.jp/k-12curriculum/info/ms/science/grade7sci/monocot/Monocot.jpg http://www.urbanext.uiuc.edu/gpe/images/mono-dicot.gif

Dicot http://www.sproutpeople.com/kids/images/seed.dicot.monocot.gif http://www.urbanext.uiuc.edu/gpe/images/mono-dicot.gif http://ednet.kku.ac.th/~sumcha/212300/graphics/extend/Dicot.jpg

Function of Plant Organs Leaf – movement of gas in/out of plant food production = photosynthesis Stem – hold leaves up to sunlight transport water, minerals and food Root – absorb water and minerals anchors plant in soil

Leaf Structure Blade – photosynthesis Veins – carry water, minerals & sugar Petiole – connects the leaf to stem, petiole http://www.greenwing.org/newgreenwing/activities/summerwebfoot%20copy/leaf-parts.gif

Leaf Tissues Epidermis – controls water loss cells without chloroplasts may have waxy cuticle Vascular – veins carries water & nutrients Mesophyll – plenty of chloroplasts “food factory”

Leaf Structure http://www.bbc.co.uk/scotland/education/bitesize/standard/img/biology/leaf_structure_al.gif

Stem - Xylem vs. Phloem Xylem water pipe mineral pipe Phloem sugar pipe living cells

Stem Function Hold leaves up to the sunlight Conducts water and nutrients between roots and leaves http://www.ictinternational.com.au/images/SAPS1.gif

Cell Types Parenchyma – food storage, photosynthesis, cellular respiration. Thin cell walls, large vacuoles. Collenchyma – provide support for plant stem and petioles. Unevenly thickened cell walls. Sclerenchyma – specialized cells for support. Remain when cells die.

Root Type Tap root - Fibrous root – 1 straight down no central root http://www.daviddarling.info/images/tap-root_system.jpg http://www.agry.purdue.edu/turf/weeds/violet/violet%20fibrous%20roots.jpg

Root Structure root hair http://extension.oregonstate.edu/mg/botany/images/fig3-big.gif

Root Tissues Epidermis – thin layer of cells takes up water & nutrients Cortex – transports water & nutrients may store sugars & starches Vascular cylinder – xylem & phloem

Root Function Water & nutrient absorption – requires energy (ATP & O2) http://www.egurucool.com/images/is/imgRep/82/2206/17.gif

What moves water? Adhesion – attraction between water and other molecule Cohesion – attraction between water molecules Capillarity – combination of adhesion & cohesion moves water up a small solid tube, such as xylem

Transpiration Evaporation of water from plant leaves http://www.agr.gc.ca/nlwis-snite/pub/ha_sa/img/box31A.jpg http://www.mrothery.co.uk/images/Image88.gif

Transpiration Pull Water evaporates from leaf Moist air sac becomes drier Spongy mesophyll cells lose water Water leaves vein, less water in vein Water from xylem replenishes vein Water from roots replenishes xylem http://www.tvdsb.on.ca/westmin/science/sbioac/plants/cohesion.gif

Transport in Phloem Organic material from photosynthesis From leaves to stems and roots – storage From roots back to leaves – spring growth Two-way traffic!! Into & out of phloem requires ACTIVE transport – energy needed for movement

Secondary Growth Annuals finish growth in one growing season. Perennials continue growth year after year. Vascular cambium produces secondary vascular tissues. Cork cambium produces periderm  bark. Cell divisions at cork cambium produce cork. Overtime the innermost core becomes heartwood. Develops growth rings each year.

Flower Parts (p. 442) carpel http://www.prairiefrontier.com/pages/families/flwrparts.jpg

Flowering Plants - Angiosperms Flower = reproductive organ Male part = anther (pollen sacs) (stamen) filament Female part = stigma (sticky surface) (carpel) style ovary Seeds develop inside the fruit

Angiosperm Reproduction Male sex cells (gametes) = pollen Female sex cells (gametes) = eggs Gamete cells are haploid Pollination = transfer of pollen from anther to stigma self-pollination vs. cross-pollination

Pollination self-pollination vs. cross-pollination http://www.fs.fed.us/wildflowers/pollinators/images/xpollination_ani.gif http://www.fs.fed.us/wildflowers/pollinators/images/selfpollination.gif

Angiosperm – Seed & Fruit Pollen lands on stigma Pollen tube grows down the style and releases two sperm nuclei 1 sperm + 1 egg = zygote → embryo (seed plant, 2n) 1 sperm + 2 polar nuclei in egg = endosperm (seed food) ovule → seed = embryo + endosperm ovary → fruit

Seed Seed = embryo + endosperm Embryo – new young plant Angiosperms – seeds inside fruit (outer coat) Ex: Orange trees Gymnosperms – seeds without fruit Ex: Pine trees http://content.answers.com/main/content/wp/en/thumb/d/db/180px-KoreanPineSeeds.jpg http://media.pegasusnews.com/img/photos/2007/11/16/2cherrypitgroesbecktn_t250.jpg

Non-flowering Plants - Gymnosperms Gymnosperms means “naked seed” – not enclosed in a fruit. An example of this occurs in pine trees and other trees that form cones – conifers Male and female cones on tree Male produces pollen Female produces eggs

Gymnosperm continued.. Do not rely on pollinators, no flowers Pollen carried by wind Adult plant – sporophyte (diploid) Immature plant – gametophyte (haploid) http://www.youtube.com/watch?v=D9byVQxvMXs&feature=player_embedded

Reproduction in Ferns Ferns do not reproduce through seeds They have no flowers, no cones, etc. Produce through spores located on the underside of the leaf.

Ferns continued….. Spores are haploid Released from plant and develop into gametophyte Gametophyte contains sex cells Requires an environment with water Male sex cells “swim” to female cells Development of new sporophyte (diploid) http://www.sciencelearn.org.nz/Contexts/Ferns/Sci-Media/Video/Fern-reproduction