An Investigation To Discover Whether Or Not There Is A Relationship Between Light Intensity And The Surface Area Of A Leaf.
The aim of this investigation is to see whether I can find a definite relationship between the light intensity onto the leaf's surface and the surface area of the leaf.
Hypothesis
I think the light intensity could affect the surface area in the following way:
·A higher light intensity could make the surface area of the leaf larger.
The reason I think a higher light intensity could make the surface area larger is the fact that there would be a larger amount of chlorophyll, containing chloroplasts, for photosynthesis. By having leaves of a larger surface area, there would be a much more efficient use of the chloroplasts (containing chlorophyll) and the high intensity light available.
Apparatus
In order to carry out this experiment we will need:
·A light probe
·A graphing calculator
·A ruler
Method
·Connect the light probe to the graphing calculator
·Program the graphing calculator to deal with light probes
·Place the light probe in the middle of four leaves.
·Make sure the light probe is pointing in the same direction as the leaves and is facing away from the leaves
·Take the light intensity reading and put it in a table of results
·Measure the length and width of each of the four surrounding leaves and record these results
·Repeat the test 15 times, trying to get a wide range of light intensities.
To make this test a fair test, I will have to control several variables. These are the temperature, the age of the leaves and the nourishment of the leaves.
To control the temperature I will be carrying out the investigation on the same day, in as short a period of time as possible.
By using the same hedge throughout the investigation, I should be able to ensure that the leaves are getting the same nourishment. As well as using the same hedge, I will also use leaves of around the same age e.g. I will not use some newly grown leaves and then test some old, dying leaves.
Results
This is my table of raw data:
This is my table to work out Spearmans rank
Hypothesis
I think the light intensity could affect the surface area in the following way:
·A higher light intensity could make the surface area of the leaf larger.
The reason I think a higher light intensity could make the surface area larger is the fact that there would be a larger amount of chlorophyll, containing chloroplasts, for photosynthesis. By having leaves of a larger surface area, there would be a much more efficient use of the chloroplasts (containing chlorophyll) and the high intensity light available.
Apparatus
In order to carry out this experiment we will need:
·A light probe
·A graphing calculator
·A ruler
Method
·Connect the light probe to the graphing calculator
·Program the graphing calculator to deal with light probes
·Place the light probe in the middle of four leaves.
·Make sure the light probe is pointing in the same direction as the leaves and is facing away from the leaves
·Take the light intensity reading and put it in a table of results
·Measure the length and width of each of the four surrounding leaves and record these results
·Repeat the test 15 times, trying to get a wide range of light intensities.
To make this test a fair test, I will have to control several variables. These are the temperature, the age of the leaves and the nourishment of the leaves.
To control the temperature I will be carrying out the investigation on the same day, in as short a period of time as possible.
By using the same hedge throughout the investigation, I should be able to ensure that the leaves are getting the same nourishment. As well as using the same hedge, I will also use leaves of around the same age e.g. I will not use some newly grown leaves and then test some old, dying leaves.
Results
This is my table of raw data:
This is my table to work out Spearmans rank