1. Carbon dioxide

2. What will happen?
lib
An increase in the carbon dioxide concentration increases the rate of photosynthesis.
So the rate of photosynthesis generally increases until limited by another factor like light or temperature.
It is normally present in the atmosphere at very low concentrations (about 0.04%), so the rate of photosynthesis is not very fast.

3. How does photosynthesis work?
lib
How does photosynthesis work?
The plants absorb carbon dioxide through the stoma of the leaves.
The plant requires carbon dioxide for photosynthesis, which allows it to gas exchange to oxygen.

4. pro It will increase the rate of photosynthesis.
lib
It will increase the rate of photosynthesis.
It is cheap to buy, so farmers buy CO2 to use in greenhouses.
Carbon dioxide is everywhere, so you can use carbon based fuels or tanks of carbon dioxide.

5. con
Lib dem
the plants will have an increase of transpiration, (water loss), limiting the growth.
Although plants need carbon dioxide, it doesn’t guarantee it.
Plants will not have a efficient rate of photosynthesis, if there isn’t a good supply of carbon dioxide

6. How can we carry out the limiting factor?
We can test the limiting factor by:
Using flowers (from same area). Collect about 5 plants.
Place plants in 5 different plant pots. But each pot in a clear plastic bag.
Place a piece of limestone into a bag. Repeat this step but with a bigger piece of limestone each time. Keep the size evenly spread out.
Create some holes to allow oxygen and water to enter.

7. 5. place each plant by a window, which allows an even amount of light and temperature. 6. Record the growth of the plant for 8-10 weeks, measuring the the increase in growth.

8. equipment flowers (any type as long as they are the same) Plant pots
Soil
Plastic.
water
Carbon dioxide ( limestone) different sizes.
The window sill.

9. How to make it fair.
Placing the flowers by the same window sill will let the plants have the same amount of light and heat.
Make sure that the plants are given the same amount of water every once a week.
Make sure the limestone is dissolving otherwise, the investigation will be faulty.
Make sure that the flowers are from same area.

10. Variables
Independent- the size of the limestone, the amount of carbon dioxide for each plant.
Dependent- the height of the flowers
Control- the location the plants will be places, the amount of water, light and temperature given.