daphnia experiment
Introduction
In this experiment I aim to find out if caffeine has an effect on the heart rate of daphnia.
Daphnia are water fleas that have a sort of heart that we can see in magnification. We can count the number of heart beats in a minute of a regular daphnia and try and get a new one with the same specifications as the old one that may have died. It is also a good idea to get a new one as we want to see how much it affects it from ordinary instead of adding the caffeine one after another. We have to be careful not to feed too much caffeine to the daphnia only a maximum of 1% as we may not be able to get a reading due to it dying.
Planning
Hypothesis
There is a correlation between concentration of caffeine solution and the heart rate of Daphnia. In this experiment, when the concentration of caffeine solution increases, the heart rate of Daphnia increases.
Null Hypothesis
There is no correlation between concentration of caffeine solution and the heart rate of Daphnia.
Scientific basis for the hypothesis
Caffeine acts as a stimulant drug, causing increased amounts of stimulatory neurotransmitters to be released. At high levels of consumption caffeine has been linked to restlessness insomnia and anxiety, causing raised stress and blood pressure.
Statistical Test
Student’s T-test: it is used for continuous data because it shows a difference between the independent and dependent variable.
After working out my student-t test, my calculated value for t is greater than the critical value of t. If it is greater it states that I will need to reject my null hypothesis. This means that I can accept my hypothesis.
Variables
The independent variable for the experiment is the presence of 5% caffeine that’s given to the daphnia which can be changed by adding a drop each time. The dependent variable is the heart rates of the daphnia which can be measured by finding the heart beat for 10s then multiply it by 6 to get it for 1 minute.
In this experiment I aim to find out if caffeine has an effect on the heart rate of daphnia.
Daphnia are water fleas that have a sort of heart that we can see in magnification. We can count the number of heart beats in a minute of a regular daphnia and try and get a new one with the same specifications as the old one that may have died. It is also a good idea to get a new one as we want to see how much it affects it from ordinary instead of adding the caffeine one after another. We have to be careful not to feed too much caffeine to the daphnia only a maximum of 1% as we may not be able to get a reading due to it dying.
Planning
Hypothesis
There is a correlation between concentration of caffeine solution and the heart rate of Daphnia. In this experiment, when the concentration of caffeine solution increases, the heart rate of Daphnia increases.
Null Hypothesis
There is no correlation between concentration of caffeine solution and the heart rate of Daphnia.
Scientific basis for the hypothesis
Caffeine acts as a stimulant drug, causing increased amounts of stimulatory neurotransmitters to be released. At high levels of consumption caffeine has been linked to restlessness insomnia and anxiety, causing raised stress and blood pressure.
Statistical Test
Student’s T-test: it is used for continuous data because it shows a difference between the independent and dependent variable.
After working out my student-t test, my calculated value for t is greater than the critical value of t. If it is greater it states that I will need to reject my null hypothesis. This means that I can accept my hypothesis.
Variables
The independent variable for the experiment is the presence of 5% caffeine that’s given to the daphnia which can be changed by adding a drop each time. The dependent variable is the heart rates of the daphnia which can be measured by finding the heart beat for 10s then multiply it by 6 to get it for 1 minute.