Lecture PPT LIfe.ppt
- 1. The Importance of Plants, their origins and ways of life Text book pages: 548-553 604, 609, 626-639, Objectives of the lecture: 1. Describe some ways that plants provide the foundation of life. 2. Provide the basic sequence of plant evolution and its relationship to changes in earth landforms and environment. 3. Describe the endosymbiosis theory. 4. Identify important adaptations of plants that enable them to live on land.
- 3. Ginkgo biloba Illustration in Pen Tsao Kang Mu of Ginkgo with seeds (1578) The only surviving species of a diverse group originating in the Permian, closely related fossils 200m ybp Motile male sperm Ginkgo biloba extract (Gbe) and two ingredients, bilobalide and ginkgolide B, are part of a review of botanicals being used as dietary supplements in the United States. Deregulation of botanicals now permits Gbe to be sold as a dietary supplement to a willing public eager to "improve brain functioning" or "promote radical scavenging activity".
- 4. Medicinal!! Ginkgo biloba- the wonder drug! What, ginkgo? I thought that was just for old people who couldn't keep a train of thought? Nope, you're wrong. Ginkgo can be a very beneficial herb to bodybuilders as well. http://www.teenbodybuilding.com/gingko.htm
- 5. Plan for Biology 220 Spring 2010 Wk 5 Th April 29 Importance of plants, their origins and problems. 6 M May 3 Tu May 4 W May 5 Th May 6 Exam The Dicot plant, morphology, meristems, cell types, and tissues Cellulose, wood structure and water transport in the plant Structure and function of the leaf. 7 M May 10 Tu May 11 W May 12 Th May 13 Stomata: structure, control, CO2 exchange and transpiration Photosynthesis I: Chemistry, chloroplast, chlorophyll, action spectra Photosynthesis II: continued Photosynthesis III: C4 and CAM photosynthesis, photo-inhibition 8 M May 17 Tu May 18 W May 19 Th May 20 Photosynthesis IV: canopy photosynthesis and global change. Translocation Plant nutrition Exam #3 on lectures May 3 through May 17. 9 M May 24 Tu May 25 W May 26 Th May 27 Plant reproduction and diversity. Plant reproduction continued Seed formation, dormancy and germination. Plant hormones and development 10 M May 31 Tu June 1 W June 2 Th June 3 Memorial Day Plant hormones and development continued. Fungi, decomposition, mycorrhizae, and lichens. Fungi continued. W June 9 Final Exam: Cumulative Plant 2:30-4:20.
- 6. Why are plants important for human life? Page 627-630 1. Plants produce oxygen 2. Plants build soil 3. Plants hold soil 4. Plants moderate the local climate 4. Plants hold water 6. Plants provide food, fuel and fibre 7. Plants provide drugs How do they do that? Green plant photosynthesis Rock weathering and carbon build-up and decomposition Root strength and ramification through soil The “reservoir” function of plants and soil Evapo-transpiration and particle capture Next slide
- 7. Figure 30-4-Table 30-1 What functions might these substances have in plants? Know 5 of these
- 8. Opium poppy, Papaver somniferum The opium poppy is the principal source of all natural opiates. Opiates are extracted from opium and poppy straw. Opium is the latex harvested by making incisions on the green capsules (seed pods). Mature seed pod of the opium poppy (Papaver somniferum) with milky latex sap dripping from a recent cut. The latex sap contains a mixture of naturally- occurring narcotic alkaloids including morphine and codeine. Morphine is acetylated to produce diacetylmorphine, better known as heroin. Evolution?
- 9. Figure 30-8 Cooksonia pertoni Seed fern leaves Cones from Araucaria mirabilis, an early gymnosperm Archaefructus, an early angiosperm Angiosperms abundant Present Diversification of flowering plants Both wet and dry environments blanketed with green plants for the first time Gymnosperms abundant Extensive coal- forming swamps Carboniferous: Lycophytes and horsetails abundant Most major morphological innovations: stomata, vascular tissue, roots, leaves Silurian-Devonian explosion Origin of land plants First evidence of land plants: cuticle, spores, sporangia 475 mya 444 359 299 145
- 10. History of evolution of major plant types on land
- 11. Life’s Timeline: The Precambrian How did multi-cellular green organisms develop?
- 12. An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis (Greek: ἔνδον endon "within", σύν syn "together" and βίωσις biosis "living"). Endosymbiosis How did multi-cellular green organisms develop? Andreas Schimper observed in 1883 that the division of chloroplasts in green plants closely resembled that of free-living cyanobacteria (blue-green algae) and tentatively proposed that green plants had arisen from a symbiotic union of two organisms. Margulis and Sagan (2001) "Life did not take over the globe by combat, but by networking" Examples: nitrogen-fixing bacteria (called rhizobia) that live in root nodules on legume roots, single-celled algae inside reef-building corals, and bacterial endosymbionts that provide essential nutrients to about 10%–15% of insects.
- 13. Anaerobic eukaryote Aerobic bacterium 2. Bacterium lives within eukaryotic cell. Pyruvate and O2 THE ENDOSYMBIOSIS THEORY FOR MITOCHONDRIA AND CHLOROPLAST EVOLUTION 1. Eukaryotic cell surrounds and engulfs bacterium. 3. Eukaryote supplies bacterium with protection and carbon compounds. Bacterium supplies eukaryote with ATP. ATP Page 604 Proposed evolutionary origin for mitochondria Each would have performed mutually benefiting functions from their symbiotic relationship. The aerobic bacteria would have handled the toxic oxygen for the anaerobic bacteria, and the anaerobic bacteria would utilize ingested food and protected the aerobic "symbiote".
- 14. Secondary Endosymbiosis Serial ingestion of photosynthetic bacteria by endosymbiontic prokaryotes or eukaryotes led to the ancestors of eukaryotic plants. All other lineages of plastids have arisen through secondary (or tertiary) endosymbiosis, in which a eukaryote already possessing plastids is engulfed by a second eukaryote. Considerable gene transfer has occurred among genomes and, at times, between organisms. As the ingested photosynthetic bacteria adapted to the ingesting prokaryotic host cell, plastids, such as the chloroplast evolved. Primary plastids are found in some algae because their plastids are derived directly from a Cyanobacterium. p609
- 15. The most convincing evidence of the descent of these organelles from bacteria is the position of mitochondria and plastid DNA sequences in phylogenetic trees of bacteria. Mitochondria and chloroplasts contain DNA There are also organisms alive today, called living intermediates, that are in a similar endosymbiotic condition to the prokaryotic cells and the aerobic bacteria. For example, the giant amoeba Pelomyxa lacks mitochondria but has aerobic bacteria that carry out a similar role. A variety of corals, clams, snails, permanently host algae in their cells. Chloroplasts have DNA sequences that indicate origin from the cyanobacteria (blue-green algae). Mitochondria have sequences that clearly indicate origin from a group of bacteria called the alpha-Proteobacteria. Multiple nuclei
- 16. Multiple ingestions lead to a variety of endosymbiotic structures
- 17. Figure 30-39 Lycopodium species Plant of the Day
- 18. Life’s Timeline: The Paleozoic Era
- 19. Atmospheric O2 and CO2 concentrations through geological time Carboniferous coal formation Origin of insect flight Denser atmosphere, Greater O2 partial pressure Widespread arthropod gigantism 70cm wing dragonfly 1m long millipede and giant spiders CO2 removed from the atmosphere by plant synthesis and limestone type rock formation
- 20. Devonian plant community Devonian plant community found at Rhynie, in Scotland. A reed-like marsh, 370-380 million years ago. Simple dichotomous branching MAIN FEATURES 15 to 30 cm tall No roots Stomata with guard cells Most had a central vascular strand Cuticle Asteroxylon had leaves –without a vascular connection Sporangia Asteroxylon
- 21. Life’s Timeline: The Mesozoic Era
- 22. Life’s Timeline: The Cenozoic Era
- 23. The land that plants colonized was hostile to life. Land plants required several adaptations to be successful that require multi-cellular tissues Adaptation to living on land mechanical strength for support, exposed light catching surfaces, anchoring system, conducting system for water, system for obtaining mineral nutrients, a way to restrict water loss in desiccating air, a means of reproducing and dispersing on land Soil development was minimal.
- 24. Things you need to know ... 1. Why plants are important for human life. 2. Some drugs derived from land plants. 3. The geological time periods when plants of different types were abundant and how this relates to the environment of those periods. 4. The adaptations shown by plants to living on land.