Unit 2 Plants and People Photosynthesis creates the food we eat and the oxygen we breathe o Carbon dioxide Water Sugars Oxygen Why study plants o To help conserve endangered plants and threatened environments o To learn more about the natural world o To better harness the abilities of plants to provide us with food medicine etc Rwanda scene of ethnic genocide in 1994 1996 o 500 000 Tutsi were murdered and another 1 million fled o Rwanda is one of the most densely populated nations in the world 10 624 million Population more than tripled between 1960 2010 2 3 of an acre per person ICLICKER QUESTION What was the conflict in Rwanda about C Resources The world population grows and grows o Per capita food production has increased Plant growth is often limited by water o Productivity also depends on the availability and cost of fertilizer What is a plant o Plants are green Mode of nutrition photosynthesis o Plant s don t move Structure and organization they have rigid cell walls o Plants have flowers Mode of reproduction ICLICKER QUESTION Are fungi plants B No Carl Linnaeus o 18th century Swedish Doctor and Naturalist o Laid the foundation for current biological classification systems o The Binomial System o Classification of plants based on reproductive structures o Classification of Organisms Kingdom King Plants Animals Bacteria Fungi Protista Phylum Class Order Family Genus Species Plays Chess On Fine Glass Stools Organisms are classified based on their evolutionary genetic relatedness o Photosynthesis began 3 Billion Years Ago o Life began 3 5 Billion Years Ago o Bacteria separated form other groups 2 Billion Years Ago o Animals and Fungi separate 1 Billion Years Ago The Green Plant Kingdom o 450 MYA Plants invaded the land o 400 MYA Transport tissues o 375 MYA Leaves o 305 MYA Seeds and pollen o 150 MYA Flowers and fruit What is our energy future o Burning fossil fuels is raising the Earth s temperature due to CO2 emission o Emissions broke down Oil 40 Natural gas 23 Coal 20 Nuclear 8 Renewables solar hydroelectric geothermal biomass wind 7 o Solix biofuels algae facility in New Mexico Growing algae for oil extraction Can be used as fuel cars jet fuel etc Currently about 8 per gallon Using renewable energy sources reduces CO2 emissions but some sources are better than others Crop Product Emissions of existing US crop land needed to meet half Us fuel demands Corn Alcohol 85 200 ICLICKER QUESTION What is the ultimate source of energy for life on earth A The Sun Cell Theory o All organisms are composed of cells the cell is the basic unit of life and all cells arise from preexisting cells o Scientific theory A well confirmed broad explanation of a natural phenomenon based on knowledge that has been repeatedly confirmed through observation and experimentation o Scientific Hypothesis A proposed explanation for a natural phenomenon o All living things are made of cells Cell membrane nucleus cytoplasm etc Plant cells have cell walls and chloroplast but animals don t Chloroplasts in leaf cells carry out photosynthesis o Creates sugar for growth and energy o Releases O2 o During photosynthesis plants lose large amounts of water Transpiration Losses due to Transpiration causes wilting which reduces growth and can cause death o Xylem moves water form the roots to the leaves o Phloem moves sugar from leaves to roots o Guard Cells and Stomates Guard cells in the leaf surface create pores Stomates Most water transpired by plants is lost through the stomates o Plant cell walls are composed of long chains of sugars particularly Cellulose Wood is 60 Cellulose Carbon Cycle o Photosynthesis CO2 H2O Sugars O2 o Respiration Sugars O2 CO2 H2O Energy Use of the Corn Crop o Almost 100 of ethanol comes from corn o In 2005 the Federal Government mandated that gas for cars must be mixed with ethanol The price of Corn has tripled since 2005 This resulted in the price of beef going up 65 and beef 55 How plants are put together o Shoot and Root o Shoot Stem Leaf Petiole Shoot Tip Lateral Buds dormant shoot tips o Root Root Tips o Plants flower based on temperature and day length o Plants grow by producing new cells at the tips of the shoot and root The cells increase in size o Practical Botany Removing the shoot tip causes the lateral buds to grow out Plants can be multiplied by making cuttings of branches and making the plant bushier rooting them in water o Stem Inside you can see the plumbing Vascular tissue bundles of Xylem and Phloem ICLICKER QUESTION Which of the following is responsible for the transport of water from the roots to the leaves B Xylem o Most plants that live more than one year perennials grow in width as well as length thickness Cell division in the body of the stem and the root increase o Why doesn t a fence bend outward when the tree grows around it Growth and length goes up and outward Reproduction Flowers Seeds and Fruits o Basic Flower Parts Pistil female Stigma Style Ovary petal and Ovule Ovule contains the seed Stamen male Anther and Filament Most flowers are hermaphroditic have both male and female structures o The ovary contains one or more ovules Ovule contains the egg After fertilization the Ovule becomes the Seed the Egg becomes an embryo a young plant The Ovary becomes a fruit o Each anther contains sacs where pollen form Each pollen grain contains two sperm cells When a pollen grain lands on the stigma a pollen tube grows out The pollen tube delivers the Sperm to the Egg Pollination the process in which the pollen grain is delivered to the stigma o Fertilization Sperm Egg Embryo After Fertilization a developing seed contains an embryo Seed Cotyledons Storage leaves Endosperm food for the young plant Embryo In some plants the endosperm is digested as the seed develops Seed Coat and is replaced by cotyledons The nutrition we get from a bean seed comes from the cotyledons A corn seed is mostly endosperm After fertilization the ovary becomes a fruit ICLICKER QUESTION Pollination is the transfer of pollen from the anther to the stigma Fertilization is when the sperm cell and egg cell merge to make the embryo A True Seedless Fruits watermelons grapes and bananas o How does this happen Make a genetic cross between two species who are closely related and get a hybrid that is sterile like a mule Or treating plants with chemicals or hormones Pollination o Economic Impact of Pollination insect o Wind Pollination 35 of crop production in the US is dependent on pollination by Flowers of
View Full Document
Unlocking...