1. Sofyan Ahmed Abdalla milaitan

2. Limiting factor
A limiting factor is the factor that limits the rate of reaction
There are a lot of factors that affect the rate of growth for a plant and light intensity is one of them
Light is used along with carbon dioxide and water for plant growth through the process of photosynthesis.

3. Effect of light on a plant
In photosynthesis there are 2 phases and they are light dependant phase and light independent phase which is also called Calvin cycle
Light is used in the light dependant phase of photosynthesis and the energy from light propels the electrons from a photosystem into a high energy state.
In plants there are two photosystems, photosystem one and photosystem 2 and are both found in the thylakoid membrane of the chloroplast.
The thylakoid membrane absorbs photon energy of different light wavelengths

4. what happens when light intensity changed?
So if light intensity is decreased this would affect the rate of photosynthesis so the rate of photosynthesis would decrease because less photon energy would be absorbed by the thylakoid membrane. And therefore if light intensity is decreased the plant growth rate would be decreased.
Light also affects plant distribution because plants are normally found in places where they are exposed to light so they can have more high energy electrons for the light dependant phase.

5. Light intensity investigation
I am going to test the affect of light intensity on a tomato plant growth and to do that we will be measuring the rate of photosynthesis. Equipment: Lamp Meter ruler Tomato plant

6. Variables
The independent variable would be the distance between the lamb and tomato plants and the distances we are going to use are 10cm, 20cm, 30cm, 40cm, 50 cm
The dependant variable would be the height of each plant after 1 month
In this investigation we are going to control:
The same type of plant
The same amount of water
Try to keep the temperature the same

7. Method
I am going to have 5 tomato plants which have approximately the same number of leaves and are roughly the same height, and we are going to put them In a dark room (separate room) set each of them at a distance of either 10, 20, 30, 40 or 50 cm away from the lamp and leave them for one month.
I am going to need to add the same amount of water, so water them all once a day for a month
And then at the end measure the height of each plant at the end of the month