Domain Eukarya Kingdom Plantae What makes a plant a plant? Cell wall primarily of cellulose Starch as primary photosynthetic storage product Multicellular with tissue development Chl a, Chl b, xanthophylls, carotenoids

Plant evolution simplified Radiates from simple to more complex – in both form and environments Seedless non-vascular Seedless vascular Seed producing, vascular Seed producing, vascular, fruits/flowers

Semi-aquatic to more terrestrial Primitive plants –Everything from aquatic environment Gas, water, light, buoyancy support Complex plants –Adapt to two environments Shoot system Root system

Plants: categorized by structures and lifecycles… Alternation of Generations

Moss sporophytes and gametophytes gametophytes sporophytes

Moss antheridia Sperm

Moss antheridia w/sperm

Moss archegonia ovum

Moss archegonia 2 ova

Moss archegonia 3

Moss sporophytes

Moss capsule (sporophyte) Operculum Spores

Liverwort

Liverwort antheridiophore

Liverwort antheridiophore 2

Liverwort antheridia Antheridiophore sperm

Liverwort antheridia w/sperm

Liverwort archegoniophore

Liverwort archegonia w/ova Archegoniophore Archegonium ovum

Liverwort sporophyte Archegoniophore

Liverwort sporophyte 2 spores

Liverwort gemmae cups(cupules)

Gemmae cups (cupules) Gemma cup (cupule) gemma

Hornwort sporophytes gametophyte

Hornwort 2 “Horn –like” Sporophyte gametophyte

Tracheophytes ancestral e.g. Rhyniophyta Ferns and “fern allies” Seedless Vascular plants –Xylem composed of Tracheids – tapered porous cells capillary action moderately efficient Sporophyte dominant

Psilophyta

Psilophyta gametophyte

Lycophyta strobila leaves

Lycophyta strobilus megaspores microspores sporophylls

Lycophyta strobilus 2 megsporangium Microspores Megaspores

Lycophyta gametophyte

Sphenophyta strobilus

Sphenophyta strobilus

Sphenophyta gametophyte

Pterophyta sporophyte

Pterophyta sporophyte2

Fern frond w/ sori

Sori on fern leaflets

Sorus

Fern sporangia Sporangium Annulus Spores

Fern sporangia and spores

Fern gametophyte

Gametophyte w/antheridia Gametophyte (prothallus) Antheridiasperm

Antheridia w/sperm Antheridium sperm

Gametophyte w/archegonia Archegonia

Gametophyte w/archegonia 2 Archegonia

Archegonia on surface of prothallus

Fern sporangium and prothallus Sporophyte Gametophyte (prothallus)

Fern Life Cycle

Pine lifecycle a

Pine lifecycle b

Ovule to seed

Pinus staminate cones

Pinus Ovulate cone (mature)

Staminate cone with pollen Pollen grains (microspores or micorgametophytes)

Pinus microgametophytes (mature pollen grains) Generative nucleus Tube nucleus “Wing”

Pinus ovulate cone megasporophyll ovule

Pinus megasporophyll Megasporophyll Megaspore mother cell

Ovule w/megaspore mother cell Megaspore mother cell Ovule

Pinus Mega- gametophyte Ovule Ovum

Pollen tubes

Pollen tube 2 Ovule (megagametophyte)

Pinus seed Haploid endosperm (gametophyte tissue)

Cycadophyta (male)

Cycadophyta

Cycadophyta ovulate cones

Ginkgophyta

Ginkgophyta leaves

Ginkgo ovules/seeds (naked) ovules (naked) seeds

Ginkgo staminate cones

Gnetophyta Welwitschia mirabilis found in Angolan desert “desert onion”

Gnetophyta/Ephedra

Angiosperms Flowering Plants Seeds in a fruit (angio = container) Double fertilization (see life cycle) Like other pollen producers, is not dependent on water for fertilization

Flower

Flower structure (carpel) (corolla) (calyx)

Inflorescences

Anther1

Anther 2

Dehiscing anther Pollen grains

Angiosperm lifecycle

Mature pollen grains

Lilium ovary (immature)

Lilium ovule ovule Megagametophyte (embryo sac) funiculus

Dicot Seed E A= plumule B= hypocotyl C = cotyledon D = testa E = radicle

Dicot seed germination Radicle

Monocot seed Plumule Radicle Cotyledon Endosperm Embryo Testa

Monocot seed germination

Vascular tissue Transport water, nutrients and food between roots and shoots System of xylem and phloem cells Varied organization in roots & shoots

Xylem cells Tracheids –Tapered, pits on ends, less capillary action vs. vessel elements –Primitive plants Vessel elements –Pits on sides, open ends –Stacked to form long tubes –Advanced capillary action –Less primitive plants Transpiration –Roots → shoots → leaves → out

Phloem cells Sieve tubes –no nucleus nor organelles –Open sieve plates Companion cells –Nucleated –Adjoined to sieve tubes via plasmodesmata –Controls sieve tubes; regulates movement Translocation –Movement of sugars; sources to sinks leaves → roots, fruits, &/or meristems

Plant Structure Apical meristem –Mitotic division –Stem & root tips –Primary growth (length) Ground meristem –Mitotic division –Ground tissues: Parenchyma – large; storage Collenchyma – smaller; flexible support Schlerenchyma – lignified; rigid support; woody Cambium –Mitotic secondary growth –e.g. Vascular cambium –e.g. Cork cambium

Leaf bud Ground meristem

Leaf bud Apical meristem –Mitotic embryonic tissue of stems and root tips –Primary growth (linear Provascular tissue Ground meristem Apical meristem

Monocot root Dicot root Vascular bundles centered in roots Cortex = outer layer Pith = center tissue Stele = pith + vascular tissue

Monocot root 2 Parenchyma Pith (Parenchyma)

Monocot root 3 Endodermis

Dicot root 2 Parenchyma

Dicot root 3 Endodermis and casparian strip Pericycle Phloem Xylem Vascular cambium

Vascular bundles –Xylem, phloem, and cambium in between –Scattered throughout monocot stems –Organized around periphery of dicots Cambium –Mitotic secondary growth –e.g. Vascular cambium –e.g. Cork cambium

Monocot stem

Monocot stem 2 Sclerenchyma Phloem Sieve element Companion cell Xylem vessel Air space Inside Outside

Dicot stem

Dicot stem 2 sclerenchyma Vascular cambium phloem

Woody stem Summerwood Springwood

Woody stem 2 Vascular cambium Phloem Phloem ray Xylem Cork

Woody stem 3 Cork (collenchyma tissue) Vascular cambium

Fruit – ripened ovary that protects the seeds Ripened? Layers of the ovary –Pericarp –Mesocarp –Endocarp

Fleshy fruits One or more ovarian layer is fleshy –Drupe Endocarp is hardened; pit or stone Peaches, nectarines, apricots, etc –Berry All or most pericarp is fleshy Grape, tomato, etc –Pepo Berry with hard thick rind Melons, pumpkins, etc –Hesperidium Berry with leathery rind Citrus –Pome Swollen receptacle around ovary or core Apple, pear

Dry fruits Lacks fleshy tissue –Dehiscent fruits Split along a seam to disperse seeds Legumes – two seams Capsules – multiple seams Bean, pea pods, peanuts, etc –Indehiscent Do not split on a seam Achenes, grains, nuts Corn, wheat, etc

Simple fruits –Single ovary of one flower Aggregate fruits –Many ovaries of one flower Multiple fruits –Many ovaries of many clustered flowers (inflorescence) Accessory fruits –Tissue other than ovary ripens (swollen)