Required practical activity

• Plants make their own food using photosynthesis, which is important not only for the plants themselves, but for the other organisms that feed on the plants.
• The food that plants produce is important, not only for the plants themselves, but for the other organisms that feed on the plants.
• The volume of oxygen produced could be measured by collecting the gas produced in a gas syringe.
• The dependent variable is the number of bubbles produced per minute.
• The areas that had no chlorophyll remain pale.
• Care must be taken when using water near electrical equipment.
• The leaf is dipped in boiling water to soften it.
• The effect of chlorophyll on photosynthesis can be investigated using a variegated plant.
• The changes in the oxygen concentration in the water could be measured using data logging equipment.
• Ensure that your hands are dry when handling the lamp.
• Control variables in the experiment include the concentration of sodium hydrogencarbonate solution, temperature, and using the same piece of Cabomba pondweed each time.
• Make sure that no Bunsen burners are turned on as the ethanol is highly flammable.
• Care must be taken when using boiling ethanol.
• The leaf is left for 10 minutes in hot ethanol in a boiling tube to remove the chlorophyll.
• Only those areas of the leaf with chlorophyll photosynthesise.
• The independent variable in the experiment is the distance from the light source/light intensity.
• Variegated plants have regions of their leaves with, and without, chlorophyll.
• Variegated plants test positive for starch, which is built up from the glucose produced.
• The leaf is spread out in a Petri dish and covered with iodine solution.
• The effect of different wavelengths of light on photosynthesis can be investigated using coloured acetate filters.
• The leaf of a variegated Pelargonium is dropped in boiling water to kill and preserve it.
• The areas that had the chlorophyll stain blue-black.