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VASCULAR TISSUE AND TRANSPORT. Plants rely on specialized tissue, called vascular tissue , to transport water, nutrients, and the products of photosynthesis around the plant. The 2 types of vascular tissue are xylem and phloem. Xylem (zy-lum).
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VASCULAR TISSUE AND TRANSPORT • Plants rely on specialized tissue, called vasculartissue, to transport water, nutrients, and the products of photosynthesis around the plant. • The 2 types of vascular tissue are xylem and phloem.
Xylem (zy-lum) What is xylem? Transports water from the roots up to the rest of the plant in one way flow. What are tracheids? Hollow cell in xylem with thick cell walls that resist turgorpressure
Capillary Action & Transpiration • Water rises through the thin tubes by a process called capillary action (cohesion of h20 molecules and adhesion to solid surface). The thinner the tube, the higher the water will rise. • Plants lose water through their stomata in a process called transpiration. As the leaves lose water, more is drawn up the plant (like liquid through a straw). • The actions of these two forces, along with rootpressure (Root pressure occurs in the xylem when the soil moisture level is high either at night or when transpiration is low during the day), allows water to be delivered to the entire plant, even to ones that are a hundred feet tall.
Phloem • Vascular tissue that transports sugars (glucose) produced by photosynthesis to plants in a two-way flow to the roots of the plant. -dripping sap(sugars) coming from a tree is usually from the phloem
Guard cells: • cells that open and close the stoma • Stomata: openings in leaf’s surface; when open: • GAS EXCHANGE: Allows CO2 in & O2 out of leaf • TRANSPIRATION: Allows excess H2O out of leaf
Transpiration: loss • of excess water from plant leaves • 2. Significance: • Transpiration causes enough pressure to help pull water (& required nutrients) up stem from roots. • As part of the water cycle, trees transpire water back into the atmosphere. • Transpiration provides much of the daily rain in rainforest. A average size maple tree can transpire 200 liters of water per hour during the summer. Transpiration is the #1 driving force for pulling water up stems from roots.