Daphnia Heart rate - Lab Report Essay Example
The affect of caffeine on Daphnia Heart rate
Aim: To see the effect of caffeine on the heart rate of the water flea Daphnia.
Introduction:
Caffeine is a stimulant which is derived from leaves, flowers and seeds of plants. The plant uses the caffeine as a way to repel insects as it is used as a natural pesticide by paralyzing and killing certain insects. It is used as a stimulant to human the central nervous system by increasing the stimulatory of the neurotransmitters, however high levels of caffeine to the body can cause effects of insomnia, stress, anxiety, weight loos or high blood pressure. In this investigation the effect of caffeine was observed on Daphnia [figure 1] a water crustacean, commonly known as a water flea, normally found in a aquatic areas like ponds, lakes, streams or rivers. They were used because this species of water fleas has a transparent exterior and it is easier to observe the heart rate of the Daphnia through the microscope.
[Figure 1] Daphnia
Variables
Independent variables:
Same volume different concentration of caffeine
Dependant variables:
Heart rate of Daphnia
Controlled variables
Time
Temperature
Size of Daphnia
Method Equipment
Cavity slide
Small piece of cotton wool
Pasteur pipette
Caffeine at different concentrations
Microscope
Tally counter
A piece of wool is teased and made into a small loop
The woollen loop is placed onto a cavity slide
A Daphnia is picked out from a beaker containing the Daphnia with a pipette and then placed in to the loop on the cavity slide
The Daphnia used have been left to refrigerate so that the heart rate has been lowered.
Immediately after placing the Daphnia onto the slide add pond water was added or the first concentration of the caffeine but adding the same volume each time just different concentration.
The Daphnia was placed onto the microscope with a low lighting.
Using the tally counter the heartbeat of the Daphnia is counted for 30 seconds.
Aim: To see the effect of caffeine on the heart rate of the water flea Daphnia.
Introduction:
Caffeine is a stimulant which is derived from leaves, flowers and seeds of plants. The plant uses the caffeine as a way to repel insects as it is used as a natural pesticide by paralyzing and killing certain insects. It is used as a stimulant to human the central nervous system by increasing the stimulatory of the neurotransmitters, however high levels of caffeine to the body can cause effects of insomnia, stress, anxiety, weight loos or high blood pressure. In this investigation the effect of caffeine was observed on Daphnia [figure 1] a water crustacean, commonly known as a water flea, normally found in a aquatic areas like ponds, lakes, streams or rivers. They were used because this species of water fleas has a transparent exterior and it is easier to observe the heart rate of the Daphnia through the microscope.
[Figure 1] Daphnia
Variables
Independent variables:
Same volume different concentration of caffeine
Dependant variables:
Heart rate of Daphnia
Controlled variables
Time
Temperature
Size of Daphnia
Method Equipment
Cavity slide
Small piece of cotton wool
Pasteur pipette
Caffeine at different concentrations
Microscope
Tally counter
A piece of wool is teased and made into a small loop
The woollen loop is placed onto a cavity slide
A Daphnia is picked out from a beaker containing the Daphnia with a pipette and then placed in to the loop on the cavity slide
The Daphnia used have been left to refrigerate so that the heart rate has been lowered.
Immediately after placing the Daphnia onto the slide add pond water was added or the first concentration of the caffeine but adding the same volume each time just different concentration.
The Daphnia was placed onto the microscope with a low lighting.
Using the tally counter the heartbeat of the Daphnia is counted for 30 seconds.