200 likes | 214 Views
Plant Diversity I: How Plants Colonized Land. AP Biology Crosby High School. Evolutionary Adaptations. Bryophytes: Mosses Lack vascular tissue Pteridophytes Ferns Seedless plants Gymnosperms: Naked seed Angiosperm: Flowering plants. Charophyceans. Most related green algae
E N D
Plant Diversity I: How Plants Colonized Land AP Biology Crosby High School
Evolutionary Adaptations • Bryophytes: • Mosses • Lack vascular tissue • Pteridophytes • Ferns • Seedless plants • Gymnosperms: Naked seed • Angiosperm: Flowering plants
Charophyceans • Most related green algae • Similarities • Rosette cellulose-synthesizing complexes • Peroxisomes • Minimize loss of organic product during photorespiration • Phragmoplasts • Alignment of cytoskeletal elements and golgi derived vesicles
Terrestrial Plant Adaptations • Apical Meristems • Multicellular, dependent embryos • Alternation of Generations • Walled Spores Produced in Sporangia • Sporopollenin: durability • Sporangia • Multicellular Gametangia • Archegonia • Antheridia
Other Terrestrial Adaptations • Water Conservation • Cuticle: polyesters and waxes • Stomata: gas exchange • Water Transport (except Bryophytes) • Xylem: water and nutrients • Phloem: sugar, a.a. and other organic product • Secondary Compounds
Land Plants Evolved from Charophyceans 500 mya • Homologous chloroplasts • Homologous peroxisomes • Phragmoplasts • Homologous sperm • Homologous Cellulose walls (20-26% cellulose) • Molecular comparison
Bryophytes • Phylum Hepatophyta: liverworts • Phylum Anthocerophyta: hornworts • Phylum Bryophyta: mosses
Gametophyte • Dominant generation • Moss produce green, branched one-cell-thick filaments (protonema) • Few cells thick and few cm tall • Anchored by rhizoids • Lack cuticle • Separate male and female
Sporophyte • Sporophyte attached to gametophyte • Liverworts: tiny body, short stalk w/ sporangia w/ protective epidermis • Moss: • Foot • Septa • Sporangium (capsule)
Pteridophytes • Vascular systems • Microphylls • Macrophylls • Sporophyte dominant lifecycle • Homosporous • Heterosporous • Megaspores • Microspores
Phylum Lycophyta • Epiphytes: use other organisms as substratum, but are not parasitic • Some close to ground • Upright stems w/ many microphylls • Sporophylls: bear sporangia that release flammable spores
Phylum Pterophyta • Psilophytes • Psilotum: Whisk Fern • Dichotomous branching and lack of true leaves and roots • Sphenophytes • Marshes, streams or sandy roadsides • Upright and horizontal stems (rhizomes)
Phylum Pterophyta • Ferns • Horizontal rhizomes grow leaves w/ extensively branched vascular system • Leaves called fronds and divided into many leaflets • Produce clusters of sporangia (Sori) • Patterns help identify ferns • Sporangia have spring-like structures to catapult spores