Invasion of land

1. Invasion of land • Stomata: opening: allows CO2 into the leaf • Cuticle: Protects from water loss • Vascular tissue: xylem and phloem • Roots: absorb nutrients and water vs. rhizoids of moss and holdfasts of algae that don’t. • Seeds: dormancy • Fruit: seed dispersal • Flowers: pollination/reproduction

2. Cuticle • A waxy cuticle covers parts exposed to air to prevent dessication. Openings in the cuticle (stomata) allow for gas exchange and are controlled by the guard cells. Guard cells

3. Vascular tissue • xylem (water and minerals) and phloem (nutrients). • Picture shows vascular tissue in a leaf in a bundle known as a vein. These are the lines you can see in the leaf.

4. Carbon dioxide • Plants lowered the levels of carbon dioxide from 25X current levels to current levels over a period of 100 million years as they adapted to and spread on land.

5. Cuticle, Dermal tissue, ground tissue, and vascular tissue

6. Flagellated sperm vs. pollen • The more primitive plants have flagellated sperm that allow them to swim to the egg. This means that the mosses, ferns, and other primitive plants require water to have fertilization. Fern sperm Types of pollen

7. PLANT DIVISIONS

8. Plants • NOTE: We use the term Divisions instead of the term Phyla when referring to plants. • Characteristics of plant kingdom members • Alternation of generations with the diploid sporophyte generation dominant except in bryophytes

9. Plant Divisions: Bryophyta • MOSSES • Dominant gametophtye generation (green) • Also includes liverworts and hornworts • Need sperm to fertilize egg • NO vascular tissue limits height of the plant and therefore have no true roots, stems, or leaves. • haploid spores are made by meiosis in the sporangium of the sporophyte. Moss sporophyte

10. Pterophyta: Ferns • Homosporous: create one spore that is bisexual. • Vascular tissue but no seeds: allows them to get taller, but limits them to shady moist areas for reproduction. • Fronds: big “leaf like” arrangement • Fiddlehead: emerging sporophyte • Sporangium make spores on underside of fronds when reproducing.

11. Ferns • Fiddlehead • Sporangia on underside of frond • Fronds • Bisexual gametophyte

12. Gymnosperms (naked seeds) have no flowers: gingko, cycad, and conifers

13. Coniferophyta • Redwoods, firs, pines, yews, cypresses • Naked seeds: not enclosed in fruits • Wind pollination (NEEDS A LOT) • Seeds, vascular tissue • No flowers • Often needles thick with cuticle and small in size to limit transpiration.

14. Seed cones vs. pollen cones Seed cones seeds Pollen cones

15. Oldest and largest • Redwoods (400 feet tall) bristlecone pine (4600 years old)

16. Anthophyta • Flowering plants • Flower will develop into fruit that is used for seed dispersal via wind, water, or animal. • Pollination can be by wind, bird, bat, insect. • Most advanced (recent) • Gametophyte is reduced and within the flower. • Most diverse: grasses to trees

17. Monocot and Dicot • The subdivisions of angiosperms. • One cotyledon or two cotyledons

18. “cot” = cotyledon (seed leaf)

19. Monocots • Often grasses and the relatives of grasses

20. Dicots • Garden plants, trees,

21. DifferencesVascular bundle location in the stem

22. #4:Flower parts • Monocot Dicot • Petals: in multiples of 3 Petals: 4 or 5

23. #3: number of seed parts

24. #2: veination in the leaves • Parallel veins Netlike veins • Monocot Dicot

25. Flower structure: reproduction organ of some plants

26. Flower parts • Pistil/Carpel: synonym for female part • Ovary-makes the eggs within the ovule • Style-extends from the ovary away from plant • Stigma-on the end of the style it collect pollen with its stickiness • Stamen: male part of flower • Anther makes pollen • Filament – holds anther away from plant • Sepals: protect flower before blooming • Petals: attract pollinators

27. Parts: functions • Female (carpel/pistil) • Stigma is sticky “top” that collects pollen • Style is connection between stigma and ovary. • Ovary is where eggs are made in the ovules • Male (stamen) • Anther makes the pollen • Filament holds anther away from female part to allow for wind/insect to carry pollen away • Petals (collectively called corona): attracts pollinators • Sepals (collectively called calyx); protects the bud before blooming

28. Double Fertilization • Generative nucleus becomes two “sperm” through mitosis. First sperm fertilizes egg in the ovule and second sperm fertilizes polar nuclei to become triploid endosperm. Endosperm will become “food” for seed.

29. Seed and Fruit • Seed: covering (seed coat), food (endosperm) and embryo. • Dormancy vs. Germination • The ripened ovary becomes the fruit after the fertilization of the egg and formation of the seed. (Contains the seed) • Purpose: Seed dispersal

30. Seed dispersal

31. Fruit types • Simple aggregate multiple

33. Review • What division of plants has no vascular tissue? • What is made by the archegonium? • What part of the flower “catches the pollen? • What is one gymnosperm other than coniferophyta? • What part of a flower becomes the fruit? • Where do you find the sporangium on a fern?

34. More review • What process makes the gametes in a plant? • What division of plants includes the tallest trees? • What is the purpose of the fruit? • What is the food of a seed called? • What group of green algae are the closest relatives to plants? • What does the cuticle prevent? • How many flowers lead to an aggregate fruit? • What is true of plants that are heterosporous?