Biology Plants 08 29 2012 Produce vitamins caffeine morphine vanillin Biochemical factories Photosynthesis creates the food we eat and the oxygen we breath Carbon dioxide water Sugars oxygen Why study plants To help conserve endangered plants and threatened environments Learn more about the natural world Better harness their abilities Rwanda Ethnic Genocide 94 96 500 000 Tutsi were murdered 1 million fled most densely populated nations in world tripled 1960 2010 World growth What is a plant World pop Is expected to triple between 1950 to 2020 Increase production to 70 over next 40 years What are the characteristics of plants o Chlorophyll plants are green o Structure Don t move have rigid cell walls o Flowers mode of Reproduction Fungi Sacrophilic take food from other Carl Linnaeus o 18th century Swedish Doctor and Naturalist o laid the foundation for current biological classification system o Binomial system Classification of plants based on reproductive structure Polynomial Vs Binomial o Genus Species o Kingdom phylum class order family genus species Kingdoms o Plant o Animal o Fungi o Protist o Bacteria relatedness Life began 3 5 BYA Organisms are classified based on their evolutionary genetic o First organisms were bacterial o 3 BYA Photosynthesis o bacteria separated from other groups 2 BYA o Animals and Fungi separate 1 BYA o The Green Plant Kingdom Green Algae 450 MYA Mosses 425 MYA Transport Tissues 400 MYA Fern Allies 380 MYA Leaves 375 MYA Ferns 360 MYA Seeds and Pollen 350 MYA Gymnosperms 325 MYA Flowers and Fruit 150 MYA Renewable o Solar 1 o Hydroelectric 36 o Geothermal 5 o Biomass What is our energy future Oil petroleum Coal Gas burning fossil fuels is raising the earths temperature due to CO2 Emissions World energy demand is increasing o Wind Growing algae for oil extraction Currently 8 a gallon Biodiesel Product Corn alcohol ethanol over 100 of lands needed Animal Cells Cell membrane Lipid membrane Nucleus Cells brain Cytoplasm Jelly like substance that houses organelles Plants Cells have same as animals plus more Cell wall Rigid layer outside of cell membrane giving structure Chloroplast where photosynthesis occurs o No chloroplasts in roots Chloroplasts o Absorb light o Joins water and carbon dioxide to form sugars are used for growth and energy During photosynthesis plants lose large amounts of water Pipes which allow water to pass from roots to leaves through stem Transpiration Xylem Phloem Moves sugars from leaves to roots Water loss from transpiration causes wilting reduces growth and can cause death Guard Cells and Stomata s Guard cells in the leaf surface creates pores stomata that allow CO2 uptake but also water loss Plant Cell walls are composed of long chains of sugars particularly cellulose Each is made up of Glucose molecules o Strong as steel at that size o Other glucose holds the chains together like glue o Wood is 60 Cellulose Carbon Cycle CORN Crop Carbon dioxide in the atmosphere enters plants through photosynthesis then animals eat the plants Photosynthesis CO2 H2O Light Sugars O2 animals respiration Sugars O2 CO2 H2O Energy Mostly used to grow pigs cows and chicken Following this is making gasohol 2005 federal announced gas must be mixed with ethanol Almost 100 of ethanol comes from corn Price of beef and pork went up around 55 to 65 How Plants are put together Shoot more complex of the two o Stem upright portion o Leaves coming off of stems o Petiole leafs stem o Shoot tip o Lateral bud dormant shoot tips o Cell division occurs at shoot tip and then the cells increase in size Roots Plants grow at tips through cell multiplication Causing roots to grow out and stem to grow up Botany Removing the shoot tip causes the lateral buds to grow out makes the plant bushy If you cut the stem off and place it in water new roots will grow Plumbing Perennials length Epidurmas protective surface on outside Vascular tissue Xylem and phloem Plants that live more than one year grow in width as well as in The cells between the xylem and the phoelm divide and cause the width to increase Two directions of growth Annuals Plants that grow one year Tree grows around fence post Post stays where it is and width grows around it Grows upwards at Reproduction Flowers seeds and fruits When flowering starts the shoot tip makes a flower instead of leaves top and lateral buds Flowers o Most flowers are hermaphroditic Have both male and female structures Ovule contains an egg After Fertilization the Ovule becomes the SEED o The EGG becomes an embryo a young plant Anther Contains sacs where the POLLEN form Each pollen grain contains two sperm cells A third cells directs growth of the pollen o When a pollen grain lands on the stigma a pollen tube grows out Pollination o The pollen tube delivers the sperm to the egg Delivery of pollen to the stigma Pollen tube curves towards the ovule o By smell from chemical substances o Pollen tube penetrates the ovule to get to egg FERTILIZATION Sperm egg embryo Embryo o A developing seed contains an embryo a young plant o Cotyledons Storage leaves o Endosperm o Seed coat Food for the young plant Some plants the endosperm is digested as the seed develops and is replaced by the cotyledons o The nutrition we get from a bean seed comes from the cotyledon Corn seed A kernel is mostly endosperm After fertilization the ovary becomes the fruit Pollination The purpose of flowers is to bring the male and female reproductive cells together Wind Pollination Oak tree o No petals o Large stigmas o Lots of pollen Corn most grasses and wheat o Female flower ears of corn with silk stigma Animal Pollination Flowers provide attractants and rewards Rewards nectar and pollen Attractants flowers shape color scent Bee Pollination o Bee flowers have a landing platform blue or yellow colors scented and nectar as reward o Fox gloves nectar guides bees learn to recognize colors odors and outlines Bees and butterflies are generalists visiting many kinds Some flowers pollinated butterflies and moths have long nectar horns Fly pollinating flowers often look and smell like rotting flesh Bird pollinated flowers produce lots of nectar and are red and odorless birds have poor sense of smell Bat pollinated flowers make lots of nectar open at night have strong fruity or musty odors and dull colors Wasp pollination of orchids looking like a female pseudocopulation Self pollination vs cross pollination Many plants self pollinate much of the time offspring a genetically uniform
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