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Plant Adaptations . Review Questions . What make up the vascular bundle? What does each part carry? What is transpiration? What two forces aid in transpiration? . Vascular bundle phloem (hormones, sucrose, and amino acids) and xylem (water and ions).
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Review Questions • What make up the vascular bundle? What does each part carry? • What is transpiration? • What two forces aid in transpiration? Vascular bundle phloem (hormones, sucrose, and amino acids) and xylem (water and ions) The movement of water through a plant caused by the suction of water evaporating from the leafs Cohesion H-bonds between H2O Adhesion H-bonds between H2O and surfaces
Transpiration Rate • Plants have constantly monitor how much H2O is in their leaves. Why? • Need H2O for photosynthesis • What factors will effect the rate of transpiration? • Temperature water evaporation • Lightintensity increase temp and photosynthesis rate • Wind faster evaporation • Humidity higher % of water in air means less transpiration
Measuring Transpiration • To find the best condition to grow plants in, researches can measure the rate of water loss • How can we know how much is lost? • Look at how much is taken in • Potometer device shows how much water is taken in by plant over time • Small air bubble moves closer to plant as more water taken in • Meter next to bubble shows value • What shows us a great amount of water loss? • Wilting plant droops down • Why does this happen? • Not enough water to support weight of cells walls
Adapting Transpiration • What environments would cause the highest transpiration rates? • Hot, dry, and bright areas; deserts • Xerophytes desert plants • Smaller leaf surface area less water loss • Thick, waxy cuticle less water loss • Water-storing tissue • Large root system absorb more water • Shiny cuticle reflects sunlight • Stomata closed during the day get CO2 at night time
Adapting Transpiration • What environment wouldn’t require transpiration? • In or on a body of water • Hydrophytes grow in or on water • Few xylem absorb water directly • No root hairs roots act are anchors • No cuticle no need to limit water loss • Stomata on upper side of leaf • Air pockets in stem gases diffuse in water slower, so air pockets increase diffusion rates and can store gases till needed
Adapting Transpiration • What environment is transpiration most consistent? • Normal temperatures and water supply • Mesophytes garden plants • Normal amount of xylem • Waxy cuticle to lower water loss • Med. sized root system • Standard plant adaptations • Many produce flowers for pollination
Moving Nutrients • What products are made in the leaves that the rest of the plant requires? • Glucose (in sucrose form), fats, and amino acids • What part of the plant needs these the most? • Root tips; always growing • Translocation movement of nutrients through the phloem for use or storage • Source and Sink system: • Supply area is source (high conc.) and area it is needed is sink (low conc.) • Nutrients actively removed causing pull of thick sap down to roots • Nutrients absorbed when passing by a sink