Major lineages and life cycles of land plants Green plants: viridiplantae Green plants Embryophytes (land plants) Bryophytes Tracheophytes (vascular plants) Seed plants Green algae Gymnosperms Angiosperms Mosses Hornworts Ferns Ferns Liverworts Lycophytes Green plants: viridiplantae Green plants Green algae life.umd.edu Embryophytes (land plants) Nitella (Characeae) embryo sporopollenin cuticle algalweb.net Coleochaete Land plants: embryophyta Embryophytes (land plants) Bryophytes Tracheophytes Anthoceros (vascular plants) tracheids Ceratadon stomata Marchantia Vascular plants: tracheophyta Tracheophytes (vascular plants) Seed plants (Gymnosperms +Angiosperms) Polypodium seeds pollen true leaves (megaphylls) Lycopodium Seed plants: spermatophyta Seed plants Pinus Gymnosperms Conifers Gnetophytes Ginkgo Cycads Angiosperms Welwitschia Ginkgo Zamia Gymnosperms brevifolia Taxus plicata Thuja monticola Pinus Chaw et al., 2000 Angiosperms Seed plants Gymnosperms Angiosperms triploid endosperm reduced female gametophyte bitegmic ovules carpel sieve tubes ovary ovule placenta Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one&or&three&apertures&(tricolpate)& Floral&parts&in&mul5ples&of&three& Floral&parts&in&mul5ples&of&four&or&five& Leaf&veina5on&parallel& Leaf&veina5on&re5culate& Vascular&bundles&sca=ered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven55ous&roots&only& Primary&and&adven55ous&roots& Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one/three&apertures&(tricolpate)& Floral&parts&in&mul5ples&of&three& Floral&parts&in&mul5ples&of&four&or&five& Leaf&veina5on&parallel& Leaf&veina5on&re5culate& Vascular&bundles&sca=ered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven55ous&roots&only& Primary&and&adven55ous&roots& Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one&or&three&apertures&(tricolpate)& Floral&parts&in&mul<ples&of&three& Floral&parts&in&mul<ples&of&four&or&five& Leaf&veina5on&parallel& Leaf&veina5on&re5culate& Vascular&bundles&sca=ered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven55ous&roots&only& Primary&and&adven55ous&roots& Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one&or&three&apertures&(tricolpate)& Floral&parts&in&mul5ples&of&three& Floral&parts&in&mul5ples&of&four&or&five& Leaf&veina<on&parallel& Leaf&veina<on&re<culate& Vascular&bundles&sca=ered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven55ous&roots&only& Primary&and&adven55ous&roots& Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one&or&three&apertures&(tricolpate)& Floral&parts&in&mul5ples&of&three& Floral&parts&in&mul5ples&of&four&or&five& Leaf&veina5on&parallel& Leaf&veina5on&re5culate& Vascular&bundles&scaCered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven55ous&roots&only& Primary&and&adven55ous&roots& Monocots vs. dicots Monocot& Dicot& One&cotyledon& Two&cotyledons& Pollen&with&one&aperture&(monosulcate)& Pollen&with&one&or&three&apertures&(tricolpate)& Floral&parts&in&mul5ples&of&three& Floral&parts&in&mul5ples&of&four&or&five& Leaf&veina5on&parallel& Leaf&veina5on&re5culate& Vascular&bundles&sca=ered&throughout&stem& Vascular&bundles&arranged&in&a&ring& Adven<<ous&roots&only& Primary&and&adven<<ous&roots& Angiosperm phylogeny Dicots with monosulcate pollen = paraphyletic Monocots = monophyletic Dicots with tricolpate pollen = monophyletic Eudicots (tricolpates) Angiosperm phylogeny Soltis et al., 2011 Rosids& Saxifragales& Asterids& Caryophyllales& Ranunculaceae& Monocots& Magnoliids& ANITA&grade& Life cycles: animals vs. plants Life cycles: plants Alternation of generations cycle between haploid (1n) and diploid (2n) phase. =&fer5liza5on& http://en.wikipedia.org/wiki/Alternation_of_generations Life cycles: plants devbio.com Life cycles: plants devbio.com Life cycles: plants Pollina5on& devbio.com Life cycles: pollination and fertilization Seed plants Gymnosperms Angiosperms triploid endosperm reduced female gametophyte bitegmic ovules carpel sieve tubes ovary ovule placenta Life cycles: pollination and fertilization pollen grain pollination = male gametophyte pollen tube ovule ovary embryo sac = female gametophyte fertilization micropyle Life cycles: review Pollination – transfer of pollen from anther to stigma (or male cone to female cone). Occurs only in seed plants. Fertilization – fusion of egg and sperm to form zygote. Occurs in all sexually reproducing organisms. Zygote in embryophytes becomes embryo. Sporophyte – the diploid (2n) generation in plants. Embryo becomes sporophyte. Produces spores. Spore – the haploid product of meiosis. Gametophyte – The haploid (1n) generation in plants. Spore becomes gametophyte. Produces gametes. Gamete – the haploid cells that participate in fertilization: egg and sperm. Gametes in embryophytes are produced by mitosis. .