What is a plant?

1. What is a plant?

2. What is a plant? • An organism that is Photosynthetic, • eukaryotic, • multicellular with a cell wall made of cellulose, • contains chloroplasts, • and lacks the power of locomotion.

3. Plant cells

4. Ancestor of algae & • plants. • Formed by a Union • between a • Protozoan-like host and A cyanobacterium (a Bacteria that uses • photosynthesis for • Energy). • It moved into the cell & became the • chloroplast of the first algae.

5. History • 1st plants emerged from ocean 3.4 billion years ago • Algae dominated the ocean of the Precambrian times • Somewhere between 400 – 500 million years ago algae made the transition onto land • Origin: green filamentous algae (Spriogyra)

6. 1st land plants • Struggle to: • Maintain water in cells on land • Exchange gases • Support self outside of water • Reproduce on land • Anchor selves on land

7. First Plants Caused Ice Ages, New Research Reveals • the invasion of the land by plants -- a pivotal time in the history of the planet -- brought about huge climate changes. • removed carbon dioxide from the atmosphere, forming new carbonate rocks in the ocean. This cooled global temperatures by around five degrees Celsius. • Our discovery emphasises that plants have a central regulatory role in the control of climate: they did yesterday, they do today and they certainly will in the future." • ScienceDaily (Feb. 1, 2012)

10. Vascular plants appeared 350 million years ago Forests followed 50 million years later Swamp forests of Carboniferous period formed the fossil fuel deposits that power us today

13. Seed plants came next • Cone-bearing plants came first • Followed by flowering plants (140 mya) • Today 96% of all plants are flowering

16. Bryophytes • Hornworts, liverworts, mosses • Non-vascular • One cell thick – absorbs water by osmosis • No roots, stems, or leaves • Reproduce by spores & alternation of generation. Gametophyte generation dominant. • Needs water for reproduction

17. Bryophytes 1st land plant One cell thick – each cell absorbs water from environment No roots, stems, or leaves – lives in moist environment Gametophyte dominant generation – needs water for sexual reproduction

24. Plants move away from water: • vascular tissue for transport, • lacks protective seed. • Vascular tissue forms xylem to transport water phloem to transport sugar

25. Pterophyta – ferns & horsetails

26. Ferns

30. Seed Plants • Conifers – seeds in cones • Gymnosperms • Flowers – seeds in flowers • Angiosperms

39. Pine, Eastern White Pine, Loblolly Pine, Longleaf Pine, Pitch Pine, Pond Pine, Shortleaf Pine, Slash Pine, Spruce Pine, Table Mountain Pine, Virginia

45. Eastern Red Cedar