Biology Paper 2
Edexcel GCSE
Complete notes for a grade 9
Complete with:
- Concise notes and diagrams
on every point on the
specification
- Provides support on core
practical
- Builds up knowledge with
detailed examples
, Plants and their functions
Photosynthesis
Photosynthetic organisms are main producer of food and have highest biomass as take energy
directly from the sun.
Plants and algae= photosynthesise= endothermic reaction (use light to react carbon dioxide+
water glucose+ oxygen).
Carbon dioxide found in air (into cell by diffusion), water in soil, glucose= sugar (fat store
respiration, cellulose, starch polymers like sucrose), oxygen is by-product.
Limiting Factors
Limiting factors= low temperature, dim light, low carbon dioxide concentration.
You can measure effect of light intensity on rate of photosynthesis, see how much oxygen given
off by pondweed. Put light source at different distances = diff light intensities.
Carbon dioxide is limiting factor as increasing it means the rate of photosynthesis will increase,
however at the end, something else must be the limiting factor as increasing the carbon dioxide
concentration stops effecting the rate of photosynthesis. (Same graph will be produced for light
intensity).
Edexcel GCSE
Complete notes for a grade 9
Complete with:
- Concise notes and diagrams
on every point on the
specification
- Provides support on core
practical
- Builds up knowledge with
detailed examples
, Plants and their functions
Photosynthesis
Photosynthetic organisms are main producer of food and have highest biomass as take energy
directly from the sun.
Plants and algae= photosynthesise= endothermic reaction (use light to react carbon dioxide+
water glucose+ oxygen).
Carbon dioxide found in air (into cell by diffusion), water in soil, glucose= sugar (fat store
respiration, cellulose, starch polymers like sucrose), oxygen is by-product.
Limiting Factors
Limiting factors= low temperature, dim light, low carbon dioxide concentration.
You can measure effect of light intensity on rate of photosynthesis, see how much oxygen given
off by pondweed. Put light source at different distances = diff light intensities.
Carbon dioxide is limiting factor as increasing it means the rate of photosynthesis will increase,
however at the end, something else must be the limiting factor as increasing the carbon dioxide
concentration stops effecting the rate of photosynthesis. (Same graph will be produced for light
intensity).
