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Plants. ROOT root tip root hairs. Roots . 1. Roots anchor plant in soil, absorb minerals & water, & store food fibrous roots (1) mat of thin roots that spread out tap roots (2) 1 large vertical root also produces many small lateral, or branch roots root hairs (3)
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ROOT • root tip • root hairs
Roots 1 • Roots anchor plant in soil, absorb minerals & water, & store food • fibrous roots (1) • mat of thin roots that spread out • tap roots (2) • 1 large vertical root • also produces many small lateral, or branch roots • root hairs (3) • increase absorptive surface area 2 3
ROOT • root tip • root hairs • STEM • nodes • internodes • buds • terminal or apical buds • axillary buds • flower buds & flowers
ROOT • root tip • root hairs • STEM • nodes • internodes • buds • terminal or apical buds • axillary buds • flower buds & flowers • LEAVES • mesophyll tissue • veins (vascular bundles)
Leaves • Function of leaves • photosynthesis • energy production • CHO production • gas exchange • transpiration simple vs. compound
Nutritional needs • plants need… • sun as an energy source • inorganic compounds as raw materials • water (H2O) • CO2 • minerals
Macronutrients • Plants require these nutrients in relatively large amounts • C, O, H, N, P, K, Ca, Mg, S
Micronutrients • Plants require in very small amounts • Cl, Fe, Mn, Bo, Zi, Ni, Mb • primarily cofactors for enzyme function
Transport in plants • H2O & minerals • transport in xylem • transpiration • evaporation, adhesion & cohesion • Sugars • transport in phloem • bulk flow • Calvin cycle in leaves loads sucrose into phloem • Gas exchange • photosynthesis • CO2 in; O2 out • stomates • respiration • O2 in; CO2 out • roots exchange gases within air spaces in soil
Water & mineral absorption • Water absorption from soil • osmosis • aquaporins • Mineral absorption • active transport • proton pumps • active transport of H+ aquaporin root hair proton pumps H2O
Mineral absorption • Proton pumps • active transport of H+ ions out of cell • chemiosmosis • H+ gradient • creates membranepotential • difference in charge • drives cation uptake • creates gradient • cotransport of othersolutes against theirgradient
Water flow through root • Porous cell wall • water can flow through cell wall route & not enter cells • plant needs to force water into cells Casparian strip
Transport of sugars in phloem • Loading of sucrose into phloem • proton pumps • cotransport of sucrose into cells down proton gradient