Econ 101 1st EditionExam # 1 Study Guide Lectures: 1 - 12Lecture 2 Photosynthesis: radiant energy from the sun is captured and used to form the sugar on which all life depends on. One of the greatest marvels of evolution, drive life on earth; only a few types of organisms – plants, algae, and some bacteria possess chlorophyll which is essential for carrying out photosynthesis.Summarized equation:6CO2 + 6H20 → C6H12O6 + 60 2 Carbon + water yields glucose + oxygen dioxide- Both products (oxygen and organic molecules) are critical to life on Earth. Role of Sunlight: it is used as an energy source in order for photosynthesis to occur.Botany – Greek for “plants”; but derived from a verb “to feed’Plants play numerous roles:1. Food2. Fiber for clothing3. Wood4. Paper5. Spices6. Drugs – medicinal plants7. Oxygen8. AestheticsTransgenic plants – genetically engineered; have created entirely new functions for plants1. Disease resistant strains2. Production of vaccines and other molecules3. Resistance to freezing4. Tolerance of high salt soil5. Production of higher levels of vitamins and nutrientsThe Evolution of Life on Earth (Key Dates)4.6 billion years ago – Earth Forms4.5- 3.8 bya – extreme meteor bombardment3.8-2.2 bya – oxygen produced but forms iron oxide. Stromatolites: fossilized microbial mats consisting of layers of filamentous and other microorganisms and trapped sediment, formed in shallow water places in Australia and the Bahamas. 3.5 bya – 1st signs of life (prokaryotic organisms)1.5 bya- 1st signs of eukaryotic organisms700 million years ago oxygen begins to accumulate 700 million years ago – first multicellular animals570-510 mya – oxygen approaches modern levels500 mya – invasion of land by plants400 mya – mosses and ferns appear360 mya – amphibians appear on land290 mya – forests of cycads, primitive conifers, ginkgo245 mya – forests of gymnosperms and ferns145 mya – angiosperms (flowering plants) appear1.6 mya – appearance of modern humans10,000 years ago – rise of agriculture, cultivation of crops10,000 years ago – rise of agriculture, cultivation of cropsPrototype Cell MembranesMicrospheresCoacervatesDNA and genetic basisStromatolites – cyanobacteria (prokaryotic & autotrophic) Cell TypesProkaryotic cells: simple cells that lack a nuclear envelope and did not have their genetic material organized into complex chromosomes. First prokaryotic cell – archaea: heat loving organisms and now thrive in extreme high temperatures & in acid environments. (ex. Bacteria)Eukaryotic cells: cells with nuclear envelopes, complex chromosomes and organelles surrounded by membranes. (ex. Everything except archaea and bacteria)Endosymbiotic theory of eukaryotic cell evolutionNutritional StrategiesHeterotrophs – probably first; is dependent on an outside source of organic molecules for its energy (ex. Mushroom)Autotrophs – “self feeders”. Without the evolution, life on Earth would soon have come to an endGeological Time TableEra Period Life Forms Key EventsCenozoic65 myaQuarternaryTertiaryAge of humansDominance by mammals and flowering plantsSpread of grasslands as forestsrecedeMore than a dozen interglacial periods in past couple million years; much cooler than Mesozoic, begins with extinction event 4Mesozoic245 myaCretaceousJurassicTriassicAge of reptiles, gymnosperms, conifers and ferns; dinosaurs flourish on landMild to warm climate for more than 100 million years, begins with extinction event 3Paleozoic570 myaPermianCarboniferousDevonianSilurianOrdovicianCambrianAge of fish, amphibians and land plants appearInvasion of land by both plants and animals, extremely cold and dry at the endof the Paleozoic; extinction events 1 and2 occurPrecambrian4500 mya3.5 bya prokaryotic organisms1.5 bya eukaryotic organismsNearly 4 billion years ofEarth’s history, origin oflife, formation of multicellular plants andanimalsTransition to Land – critical limiting factor is water, animals could move around to find water; plants had to evolve different strategiesDevelopment of roots, stems and leavesRoots: anchor the plant in the ground and collect the water required for maintenance of the plant body and for photosynthesis.Stems: provide support for the principal photosynthetic organs (the leaves)Leaves: what conducts photosynthesisCuticle: covers the epidermis, waxy, retards water loss, prevents exchange of gases between the plant & the surrounding air that’s necessary for both photosynthesis and respirationStomata: open and close in response to the environmental and physiological signals, thus helping the plant maintain a balance between its water losses and its oxygen and carbon dioxide requirementsEvolution of Plant Life CyclesAnnuals: plants with a life span of one year Perennials: longer lived plants – the stem may become a corkEvolution of Vascular TissueXylem: water passes upward through the plant bodyPhloem: food manufactured in the leaves and other photosynthetic parts of the plant is transported throughout the plant bodyPlant GrowthMeristems: embryonic tissue regions capable of adding cells indefinitely to the plant body1. Primary (10) growth – meristematic tissue (apical meristems – involved with the extensions of the plant body)2. Secondary (20) growtha. Lateral meristemsi. Vascular cambiumii. Cork cambiumReproduction on LandFertilizationReproductive structuresSporesSeed: the embryo, the supply of stored food, and the seed coat are the components. Subdivisions of BotanyPlant morphology: the study of the form of plantsPlant anatomy: the study of their internal structurePlant physiology: the study of how plants function, how they capture and transform energy andhow they grow and developPlant taxonomy and systematics: involving the naming and classifying of plants and the study ofthe relationships among themHuman Population Growth1800 – 1 billion1930 – 2 billion1987 – 5 billion2015 – 7 billionSustainability? Lecture 3Text Reference – Chapter 12Plant Systematics: The Science of Biological Diversity- Systematics: scientific study of this biological diversity and its evolutionary history; scientific analysis of diverse in logical groups. Given the tools of the time; the overrall goal is to discover all the branches of the phylogenetic tree of life - Taxonomy: science of classification that