kingdom plantae the plants- kingdom plantae · kingdom plantae the plants- kingdom plantae ......
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Kingdom Plantae The Plants- Kingdom Plantae
• Multicellular, eukaryotic, photosynthetic, autotrophic
• All have:– Chloroplasts, evolved from single-celled green
algae– Non-motile, rigid cell wall, sexual reproduction– Require light, water, minerals, CO2, other stuff
which they must get from their environment
The First Plants- The Algae
• Plant evolution begins in the sea• Single celled Multicelled colonies
– But still have very little specialization between cells
• Three divisions of algae- all can be seen in tide pools
– Rhodophyta- Red Algae– Phaeophyta- Brown Algae– Chlorophyta- Green Algae
Life cycles of most algae
• 2 multicellular phases- Alternation of Generation
• 2n n 2n n….etc.• Sporophyte and Gametophyte• One phase may be dominant in structure• Example on board and overhead
General Algal /Plant lifecycle Plants move onto LandAdvantages• Low competition• Low predation• Ample sunlight• Ample landscape• Higher CO2
Challenges• Motile sperm need water• No water to hold up body• H2O, minerals- absorb and
transport issues• Desiccation• Dispersal problems• Temperature changes• Need to protect embryos
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Water vs. Land
Evolution of Land Plants• All land plants evolved from Division
Chlorophyta, or the Green Algae– Photo pigments- Chl. a & c, Carotinoids– Store food as Starch
Bryophyta- The Mosses and Liverworts
• 1st terrestrial plants• Non-vascular- so they can’t transport water
very well…what does this mean?• Motile sperm- Need water to reproduce• Small size, gametophyte is dominant• Must live near water in a moist habitat!
Bryophytes Sphagnum, or peat moss: Peat bog in Oneida County, Wisconsin
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A peat moss bog in NorwayBryophyte lifecycle
The Vascular PlantsAdaptation Trends of Vascular Plants• Roots- obtain H2O and nutrients• Vascular tissue
– Xylem- H2O and nutrient transfer– Phloem- sugar transport
• Cuticle- prevents drying• Stomata-prevent drying and helps gas ex.• Leaves- efficient photosynthesis
The Vascular Plants, cont.
• Xylem and Lignin- support for tall stems• Hormones- coordinate growth, help with
changing conditions• Pollen- replaces motile sperm- how get
around? Wind or animals• Seeds- protects and dispersal of next gen.• Fruits- enhance dispersal- animals• Flowers- amt. pollen, pollination/fert.
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Ferns, club mosses, horse tails
Ferns• Large, many-veined leaves= Fronds• Rhizome- underground stem w/ roots• Dominant Sporophyte w/ vascular tissue.
– Independent gametophyte- Vulnerable, no roots– Still has motile sperm-Needs moist environment– Most gametophytes die or are eaten
• 25 million year period of drought and glaciation 280 mya. Strong selection pressure for desiccation resistance
Horsetail
Fern Sorus and SporangiumThe life cycle of a fern
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Life cycle of a fern: mature sporangium Life cycle of a fern: germinating
Life cycle of a fern: gametophyteFig. 15.14
The stem of a fern Xylem and phloem in the stem of a fern
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Carboniferous forest based on fossil evidence
The Gymnosperms- Pines
• The first truly terrestrial plants• Reduced and retained gametophytes-Cones• Separate sexes- self fert, outcrossing, gen. vari.• Pollen- non-motile sperm- Wind- random, expensive• Seed- Sporophyte embryo- 3 generations
nourished and protected• Needles- low evaporation• Slow life cycle- 7-10 years
Vascular tissue
Stem Tissues Sequoia
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Sequoias Cypress
Common juniper Bristlecone Pine
Oldest Living Trees
4,766 years old!!!
The life cycle of a pine The life cycle of a pine
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The life cycle of a pine
Fig. 15.14
Male pine cones Pine Sporangia with sporesPollen
Pine pollen Winged seed of a White Pine (Pinus strobus)
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Pine embryo
The Angiosperms- Flowering Plants
• Cone Flower: Flower Power!– Attractive colors, nectar, pollen- All for animals!– Specific coevolution– Non-random, efficient fertilization
• Gameto- dependent• Leaves with stomata• Short life cycle-• Fruit- efficient dispersal• Increasing specialization of vascular tissue
The typical angiosperm plant
The structure of a flower
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Pollen grainsFig. 15.5
Relationship between a pea flower and a fruit (pea pod)
Angiosperm Lifecycle
Fig. 15.14 Angiosperm Vascular Tissues
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Vascular tissue- Roots Vascular tissue- Stems
Angiosperm leaves How does Vascular tissue work?
Pollen dispersal- Smart delivery devisesSeed Dispersal
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Fruit adaptations that enhance seed dispersal: Red berries (left), dandelion (right) Dandelion seed dispersal
The Angiosperm’s other trick… Fruits Animal Dispersal
Table 15.1