Biology IA
For this experiment petri-dish A is fully exposed to the light source while petri-dish B is partially exposed to the light.
Independent Variable:
We have chosen our independent variable to be the amount of light exposed to the cress seeds. Our first petri-dish was allowed to be fully exposed to the light surrounding it, while the second was fully wrapped in black paper excluding a 0.5cm slit directed towards the sun.
Dependent Variable:
Our dependent variable is the reaction/actions to the given conditions, for example the growth of the different cress seeds, the direction of growth or if it grows at all.
Controlled Variable:
To keep the test fair we will control the variables by measuring each variable out. Our controlled variables are:
Number of cress seeds in each petri dish (15 each)
Water absorbed by cotton wool (10ml)
The location of the petri-dishes are at the same level and are both the same distance from the window. – this keeps the light source, the temperature and the supply of CO2 and O2 exposed to the plant the same.
The room temperature fluctuates, but both plants experience the same temperatures making the test fair.
The windows are kept closed because glass absorbs some of the UV light rays
Size of cotton sheet used (10cmx10cm)
Same water source used therefore no impurities
Same type of cotton from same source
Same type of plant (Cress seeds)
Method:
1) Measure out the cotton and place inside both petri-dishes
2) Pour 10ml of distilled water into each petri-dish
3) Place seeds in at even distances from each other leaving enough space for them to grow
4) Take the second petri-dish and cover it completely with black paper and cut a single 0.5cm thick slit through the paper
5) Place the petri-dish on a flat surface equidistant to the light source
6) Leave the project for a week and water crest seeds daily (10ml a day)
7) Write up observations of plant growth throughout the week and compare results
Prediction:
I
Independent Variable:
We have chosen our independent variable to be the amount of light exposed to the cress seeds. Our first petri-dish was allowed to be fully exposed to the light surrounding it, while the second was fully wrapped in black paper excluding a 0.5cm slit directed towards the sun.
Dependent Variable:
Our dependent variable is the reaction/actions to the given conditions, for example the growth of the different cress seeds, the direction of growth or if it grows at all.
Controlled Variable:
To keep the test fair we will control the variables by measuring each variable out. Our controlled variables are:
Number of cress seeds in each petri dish (15 each)
Water absorbed by cotton wool (10ml)
The location of the petri-dishes are at the same level and are both the same distance from the window. – this keeps the light source, the temperature and the supply of CO2 and O2 exposed to the plant the same.
The room temperature fluctuates, but both plants experience the same temperatures making the test fair.
The windows are kept closed because glass absorbs some of the UV light rays
Size of cotton sheet used (10cmx10cm)
Same water source used therefore no impurities
Same type of cotton from same source
Same type of plant (Cress seeds)
Method:
1) Measure out the cotton and place inside both petri-dishes
2) Pour 10ml of distilled water into each petri-dish
3) Place seeds in at even distances from each other leaving enough space for them to grow
4) Take the second petri-dish and cover it completely with black paper and cut a single 0.5cm thick slit through the paper
5) Place the petri-dish on a flat surface equidistant to the light source
6) Leave the project for a week and water crest seeds daily (10ml a day)
7) Write up observations of plant growth throughout the week and compare results
Prediction:
I