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22 Cards in this Set
- Front
- Back
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Roots - function
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Absorb nutrients and H2O and gas exchange
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Leaves
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Imput for photo - Photons and CO2
Output for photo - O2 and H2O |
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How leaves are placed affects light acquisition
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By...
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Define Phyllotaxy
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How many leaves there are and their position at the nodes. High light in Alternate, rosette and spiral. Low light in opposite, whorled and decussate.
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What is the leaf index and what is it used for?
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- to measure shading. SA of all the leaves/SA of soil.
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What is biomass?
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A measure of the amount of photosynthesis. The lower the biomass, the less the photosynthesis and the leaf index varies with it
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The orientation of leaves differs among plants. Horizontal, vertical and modified plants
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Horizontal - high light absorption, high shading
Vertical - low light absorption, low shading Modified - varies from top to bottom |
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Roots will compete with...
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each other for dominance
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What is the horizon?
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The top soil, which is nutrient dense
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Soil composition is made up of four things
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Water, air, inorganic material, organic matter and soil organisms
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Water
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source for soil organisms and roots
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Air
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root gas exchange
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Inorganic particles.
Examples Functions |
examples are clay, sand and slit. They perform cation exchange since they themselves are negitively charged and attract positively charged ions. Make minerals available to plants, contribute to soil struture and prevent clumping
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Organic matter
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aka. humus. source of nutrients released from dead matter by soil organisms. hold water, contribute to soil structure
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Soil organisms
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mix soil, contribute nutrients, decompose materials, enhance uptake of nutrients by plants BUT not all are beneficial to plants
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Fertilizers
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Ions added to the soil at the right time.
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Free living plant growth promotes growth of...
How do plants contribute? |
rhizobacteria, so named for where they live (in rhizosphere, which is soil that is bound to the roots). Plants secrete sugars which attract the bacteria and form mutually beneficial relationships.
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Rhizobacteria functions
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absorb toxins, protect plant by making antibodies. Making stubborn nutrients available to plants, as well as contributing to nitrogen cycle.
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Nitrogen cycle and bacteria
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-Fixing atmospheric nitrogen (nitrogen fixing bacteria)
- Decomposing organic nitrogen (ammonyfying bacteria) - converting ammonium to nitrogen (nitrifying bacteria) - Releasing nitrogen to atmosphere (denitrifying bacteria) |
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Nitrogen fixing bacteria
- location - association - plant helps by... - bacteria helps by... |
- in nodules of several plants
- mutualistic - providing sugar for bacteria - bacteria gives plants a usuable form of nitrogen |
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Nodule formation (4 aspects)
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-bacteria are stimulated to form an infection thread
- bacteria then penetrate the cortex with infection thread, and cells of cortex and pericycles divide and vesicles with bacteria enter cortex, create bacteroids - new pericycle and cortex cells form nodule by merging - The nodule now develops vascular tissue, which is continuous with the vascular tissue of the plant |
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Fungi and plant nutrition
- relationship - Plants provide... - bacteria provide... - ectomycorrihizae - endomycorrihizae - epiphytes - parasitic - carnivorous |
- mutualistic
- sugar (nutrition) - increase SA for nutrition and H2O absorption and give PHOSPHATES - Ectomycorrihizae (mantle and intercellular net) - most trees - Endomycorrihizae (no mantle, hyphae btw epidermal cells and cortex - Epiphytes - latch onto another plant, make own food - Parasitic plants - drain from host (mistle toe) - Carnivorous - eat insects |
