Transcript to the Unit 2 Topic 1/2 PowerPoint
Plants & People How we all connect together … People & Plants How do humans use plants? Food Fibre (building materials) Medicines Plants are vital to our survival! Plants & Ecosystems We know for humans … but for the environment? Plants filter our air (Breath in what we breath out) Plants help filter our water (Clean up dirty water) Plants help keep soil in place (Roots hold earth together) Plants & Food Mind – blowing fact … 75% of the world’s food supply is based on seven major crops … - wheat - potatoes - rice - corn - barley - sorghum - cassava Plants & Fibre While many things are manufactured … we still use 3 natural fibres! - Cotton - Flax - Hemp Cotton (Currently) The world’s most important nonedible plant! Their structure (strong, flexible, gradual spiral) makes them extremely versatile! Hemp Oldest cultivated plant in the world! Less negative effect than other fibres Hemp Factoids! Hemp paper lasts longer than wood pulp paper Ready for harvest in 1 year First Bible printed on hemp paper Nothing eats it so no pesticides required! Flax Grows in nothern, cooler regions Fibres in stems is 2 to 3x stronger than cotton Used in a variety of different process (oil paints and varnish) Plants & Medicines Before over the counter medicine existed people used the plants around them Ginger = upset stomach Bark of white willow = pain killer How Aspeirin was developed Hundreds of examples exists like Morphine, Codeine, etc … Plants & Transportation Rubber (latex) changed our world Comes from Brazilian Rubber Tree (Only source in the world) Synthetic exists but not as good Plants & Fuel Wood burned for fuel Old plants provide fuel Died Buried Compressed Structural / Chemical Changes Became Coal Burn Coal for Fuel Plant Life – Roots Plants are like icebergs, they work like this … Plant Life – Roots What do they do? Absorb minerals / water Anchor / support plant Store food Root Crops • You eat root vegetables you are eating a root! • WHOA! Diffusion & Osmosis Diffusion is key for plant roots Moving and distributing evenly from areas of higher concentrations to lower concentration Diffusion & Osmosis Diffusion is key for plant roots Moving and distributing evenly from areas of higher concentrations to lower concentration Osmosis Diffusion of water through a differentially permeable membrane (Like a mesh bag with sand and marbles … the sand can go through but not the marbles) Cells in roots are differentially permeable (Allow some things such as water & nutrients and hold the rest out) Stems Refer I to page 108 in your text book. would know that diagram of a tree trunk and the layers *hint* Stems Cont … Support They provide support for leaves so they get enough sunlight to make food Some are tiny (few mm) and some are huge (100+m long) Stems Cont … Food Storage They store food produced by the leaves Underground vegetables (i.e.: potatoe) have tubers which store food in the form of starch for the potatoes to use Factoid! The barrel cactus does this so well it can last a year without water Leaves Leaves turn green due to chlorophyll Leaves use the sun to make food turning the light into chemical energy But how…? They need to ingredients Water Carbon Dioxide Leaves Cont … Water + Cardon Dioxide = Sugar This is the plants energy storing chemical The process is known as photosynthesis! Video Explanation! Stoma/Stomata Open during day Close at night Carbon Dioxide enters and goes into chloroplasts Reaction occurs that produces sugar and oxygen Leaves Cont … Simple Video The sugar feeds the plant The oxygen is released Plant need oxygen too! At night, when no sunlight is around, plants release CO2 and absorb Oxygen This is done through guard cells (via osmosis Swell with water = open & release of CO2 & water vapour Lose water = closed This is transperation (i.e.: how water moves up) Moving Water Roots are pulling water in and it is going up via root hairs and osmosis Leaves are pulling water from xylem as well Powerful stuff!