Ph Bean Lab
Florencia Rodriguez
October 20, 2010
IB Biology SLII
The effect of three different pH levels (4, 7, 10) on the rate of germination of spanish beans
Research Question:
What is the effect of three different pH levels (4, 7, 10) on the rate of germination of spanish beans?
Independent Variable: The different pH levels in the water would be the independent variable in this lab. Three different pH levels were tested, 4, 7 and 10, both 4 and 10 were chosen because they are 3 pH levels away from 7 which would be the regular pH level of water. We measured the different pHs by using pH buffer capsules.
Dependent Variable: The change in the rate of germination of the beans was measured and this was done by recording the size of the embryos after 4 days of germination (96 hours). The bigger the embryo the more the beans had germinated, this happened mostly in the pH level 7. Six different samples of 15 beans were used so we could have two trials for each pH level.
Background:
pH levels go from 1 through 14, 1 being the most acidic and 14 being the most basic, the pH level that is the most neutral is 7. (http://jrscience.wcp.muohio.edu/nsfall98/FinalArticles/Final.TheEffectofDifferen.html) When pH levels fall below 4 or above nine, usually the organism will die. (http://www.grc.nasa.gov/WWW/k-12/fenlewis/test.htm). Soil that is too acidic or too basic does not give plants a healthy environment to grow in, this is because in both cases the plants do not get enough nutrients, which is harmful to bacteria that is helpful.
Hypothesis:
Therefore our hypothesis is that the further away the pH is from 7 the less germination the beans will go under. Although they will still go under germination since the numbers we chose were not below 4 or above 9 so therefore we just want to see how much the embryos will grow in levels 4 and 10.
Controlled Variables: 1. Germination Time
Each beaker with an amount of 15 beans in each, germinated for 4 days, the
October 20, 2010
IB Biology SLII
The effect of three different pH levels (4, 7, 10) on the rate of germination of spanish beans
Research Question:
What is the effect of three different pH levels (4, 7, 10) on the rate of germination of spanish beans?
Independent Variable: The different pH levels in the water would be the independent variable in this lab. Three different pH levels were tested, 4, 7 and 10, both 4 and 10 were chosen because they are 3 pH levels away from 7 which would be the regular pH level of water. We measured the different pHs by using pH buffer capsules.
Dependent Variable: The change in the rate of germination of the beans was measured and this was done by recording the size of the embryos after 4 days of germination (96 hours). The bigger the embryo the more the beans had germinated, this happened mostly in the pH level 7. Six different samples of 15 beans were used so we could have two trials for each pH level.
Background:
pH levels go from 1 through 14, 1 being the most acidic and 14 being the most basic, the pH level that is the most neutral is 7. (http://jrscience.wcp.muohio.edu/nsfall98/FinalArticles/Final.TheEffectofDifferen.html) When pH levels fall below 4 or above nine, usually the organism will die. (http://www.grc.nasa.gov/WWW/k-12/fenlewis/test.htm). Soil that is too acidic or too basic does not give plants a healthy environment to grow in, this is because in both cases the plants do not get enough nutrients, which is harmful to bacteria that is helpful.
Hypothesis:
Therefore our hypothesis is that the further away the pH is from 7 the less germination the beans will go under. Although they will still go under germination since the numbers we chose were not below 4 or above 9 so therefore we just want to see how much the embryos will grow in levels 4 and 10.
Controlled Variables: 1. Germination Time
Each beaker with an amount of 15 beans in each, germinated for 4 days, the