Please enable JavaScript.
Coggle requires JavaScript to display documents.
Plants - Coggle Diagram
Plants
Light Intensity Required Practical
Factors that effect photosynthesis rate
Light
Temperature
Water
Aim
To investigate the effect of light intensity on the rate of photosynthesis in pondweed
Independent variables
Light intensity
Distance
Dependent variables
Number of bubbles per minute
Controlled variables
Distance between light and the pondweed
Time counting bubbles
Length of pondweed
Uncontrolled variables
Heat energy from light source
Number of bubbles
Amount of light/heat entering the room
Repeat the investigation 3 times to reduce the chances of a human error or an anomaly result
A way to improve the investigation is to reduce the amount of heat reaching the pondweed because heat may have an effect on the capacity of the water to contain gas
Food Test Required Practical
Sugar
Chemical or reagent required - Benedict's
Basic method - Cover food sample with benedict's. Then Place in a hot water bath
Positive test - Blue →Red, Orange, Yellow or Green
Starch
Chemical or reagent required - Iodine
Basic method - Place food sample on a spotting tile. Then add a few drops of iodine
Positive test - Orange → Black or Blue
Protein
Chemical or reagent required - Sodium Hydroxide and Copper Sulphate
Basic method - Cover food with NaOH. Then add an equal amount of CuSO4
Positive test - Blue → Lilac
Fats
Chemical or reagent required - Ethanol
Basic method - Cover sample with ethanol. Then shake
Positive test - Clear → Milky
Photosynthesis - an endothermic reaction in which energy is transferred from the environment to the chloroplasts by light.
carbon dioxide + water → glucose + oxygen
CO2 + H2O → C6H12O6 + O2
The glucose produced in photosynthesis may be...
used for respiration
converted into insoluble starch for storage
used to produce fat or oil for storage
used to produce cellulose, which strengthens the cell wall
used to produce amino acids for protein synthesis. To produce proteins, plants also use nitrate ions that are absorbed from the soil.