Note by xo , updated more than 1 year ago


Note on Xerophites, created by xo on 01/05/2014.
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Xerophite adaptationsThick waxy cuticle- water can not pass through so easilyStomata sunk into pitsincreased humidity in stomatal guard cells pit decreases transpiration raterolled leavesincreased humidity and decreased air movements within the roll, decreases transpiration rateHairy leavesincrease humidity and decrease air movement within the hairy regions, this decreases transpiration rate

Xerophites a plant which has adapted to survive in environments that would cause excessive transpiration They regulate their water balance in extremely hot/dry/windy conditionsSome xerophites are adapted to survive temporary lack of water due to freezing soil conditionshydrophytes- are adapted to survive to life in watery habitats such as ponds which water levels vary throughout year. 

Account of Glycolysisoccurs in the cytoplasm of mitochondrion cellcontrolled by enzyme controlled reactionsis anaerobicis the breakdown of glucose a 6C carbon molecule into 2 3 carbon molecules of pyruvic acidis the oxidation of glucose (reduction is gain of hydrogen )overall net gain of process is 2 ATPneeds ATP to start processglucose is broken down into pyruvic acid releases hydrogen, and the hydrogen released is met by NAD, a hydrogen carrier, and hyrgrohen released is taken away as NADH

An account of the Krebs Cycle-occurs in the central matrix of mitochondrion cells is aerobic-acetyl a 2C molecule is derived from pyruvic acid created in glycolysis - CO2 is waste product -acetyl meets with co-enzyme A and forms acetyl CoA(2C)-hydrogen is met by NAD and is carried away as NADH-4C compound joins with acetyl group to form citric acid

Plants Transpiration is the evaporation of water through the stomata in plant surfaces especially the underside of leaveswater moves through the plants from the roots to the stems and out of the leaves in the transpiration stream, 1) water enters roots by osmosis or diffusion into root hair cells that have large surface area.2) water passes by osmosis down the water concentration gradient through the cells of the cortex and into xylem3) In the xylem, water molecules are held together by the force of cohesion The force of adhesion attracts water to the walls of the xylemThese two forces ensure that the treads of water present in the xylem vessels do not break.4) water evaporates from leaf cells into the air spaces of leaves5) The water vapour then diffuses into the atmosphere through the stomata

As well as supplying leaves with water for turgidity and as a raw material for photosynthesis. The Transpiration stream also supplies plant with nutrient ions and has a cooling effect on the leaves.The stoma open and close due to changes in turgor of the guard cellswhen the guard cells are turgid= the pores are open fullywhen the guard cells are flaccid- pores close.

Factors and explanation of effects which affect the rate of trans. streamFactor: increased temperature, this increases transpiration rate. Because of the increase in rate of evaporation Factor: Increased humiditydecrease of transpiration rate,as it decreases evaporation rateFactor: increased wind speedincreases transpiration rate, increases rate of evaporation.increased light:increases trans. rate. Stomata open to allow the escape of water vapour, by evaporation.

Hydrophite adaptationshydrophyte plants adapted to survive in watery habitats their adaptations include:stomata on upper surface, which allows gas exchange with airlarge air spaces on leaves - allow the leaf to stay afloat. And also keeps the plant in light, also allows contact with the air. reduced central xylem system-allows flexibility of stem creating less resistance to flowing water.

xerophites and hydrophites

glycolysis and krebs cycle

transpiration stream

transpiration factors and hydrophites

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