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Plant nutrition. Method of nutrition used by plants is: photosynthesis. Raw materials needed: CO 2 and H 2 O Conditions present: chlorophyll and sunlight~. Leaf Structure. To show presence of stomata. Section of leaf. Structure of Stomata . Stomata: open and close. close. open.
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Plant nutrition Method of nutrition used by plants is: photosynthesis. • Raw materials needed: • CO2 and H2O • Conditions present: • chlorophyll and sunlight~ GEP WeeSC
Leaf Structure GEP WeeSC
To show presence of stomata GEP WeeSC
Section of leaf GEP WeeSC
Structure of Stomata GEP WeeSC
Stomata: open and close close open GEP WeeSC
Photosynthesis • Summary equation: • CO2 + H2O C6H12O6 + O2 Products of photosynthesis: 1 sugar (built up to starch for storage) 2 oxygen. Light, chlorophyll GEP WeeSC
How to show that plant is photosynthesising • Test for presence ofstarch. Photosynthesis is the only way a plant can produce this. • How to test for starch? Use iodine solution. GEP WeeSC
To test a leaf for starch • Boil leaf in water. • Boil leaf in alcohol to remove chlorophyll • Wash in water . • Why must the leaf be boiled in water? To allow I2 solution to penetrate cells. • Why must the leaf be decolorised? To allow blue black colour to show up. • Why must the leaf be washed in water? To soften it. GEP WeeSC
To show thatchlorophyllis needed 1 Destarch a potted plant with variegated leaf by: 2 placing the plant in the light for 48 hrs. 3 Remove a leaf & test for starch. 4 Only the green parts of the leaf give a dark blue (blue- black) colour with I2 solution. GEP WeeSC
To show that light is needed • Destarch 2 potted plants. • Leave 1 in the dark (experimental). • Put one in the light (control). • All other conditions must be the same. • Leave the 2 plants for 48 hrs. • Take a leaf from each plant to test for starch In which plant will starch be present? GEP WeeSC
To show that CO2 is needed for photosynthesis • Destarch 2 potted plants. • Place 1 plant in a bell jar with a dish of soda lime to absorb CO2. • Place the other in a bell jar without CO2 (Which plant is the control?) • All other conditions should be the same for both plants. • Leave the plants for 48 hrs, then test the leaf for starch (with I2 solution). In which plant will starch be present? GEP WeeSC
To show that O2is given off duringphotosynthesis • Place some water plants eg hydrilla under an inverted filter funnel in a beaker of H2O. • Dissolve some NaHCO3 in the H2O ( to provide CO2 to the plant. • Place the apparatus in sunlight for 6 hrs. • Set up a control in the same way, but left in the dark. • Gas bubbles will only be released from the plant placed in sunlight. • This gas rekindles a glowing splint. GEP WeeSC
What happens to sugar formed in photosynthesis 1 Broken down inrespiration. 2 Built up into starch for storage. 3 Turned into fats for storage & other uses. 4 Combined with N2 to form proteins. 5 Moved to other parts of the plant. GEP WeeSC
photosynthesis GEP WeeSC
To show thatchlorophyllis needed.Use variegated leaf. GEP WeeSC
To show thatO2 is given off GEP WeeSC
To show thatO2is given off.Glowingsplint rekindles. GEP WeeSC