• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

I think that caffeine enters the daphnia's body then the heart rate will increase dramatically

Extracts from this document...

Introduction

Does Caffeine Affect Heart Rate Hypothesis: I think that caffeine enters the daphnia's body then the heart rate will increase dramatically. This is because caffeine acts as a stimulant making muscles work faster. I will count the heart beats from daphnia in water and then in caffeine and see the difference. Suitable equipment: We used a pipette to pick up the daphnia. This could injure the daphnia. Also this could startle the daphnia which would increase its heart rate therefore making it an unfair test. Risk assessment: Ethical Issues: You have to use ice water on a separate slide underneath the daphnia so that the heat from the microscope doesn't burn it. Use cotton wool to stop the Daphnia from moving about to much, this makes it easier to keep the daphnia to see and count the heart beats. ...read more.

Middle

Reliability and validity: I don't think that my results were very valid or reliable. It was very hard to count the heart beats because the heart was eating to fast to count. You might not always get the right beat for the heart either. Therefore I could have counted the heart beats wrong. One way that you could solve this problem is to use strobe lighting and set it so that it looked like the heart wasn't moving at all. You would then know that the heart was beating at the same speed as the strobe lighting. This would mean that the heart beat count was more reliable and valid. Errors There is a possibility of random error when you are counting the heart beats. ...read more.

Conclusion

I had no anomalous results. My non caffeine results had a range of 14 and my caffeine results had a range of 78 which is larger. This is because it was harder to count the heart beats when the heart was beating faster. Conclusion I think that the caffeine makes the heart of the daphnia beat faster this mean that more blood is being pumped from the heart around the body. For further investigation we could try the experiment on larger animals such as dogs or humans. Or you could try the experiment on the same animal but with different concentrations of caffeine. If I was to experiment the investigation further I would find an animal which it is easier to measure the heart rate on such a human where you can use a machine. ?? ?? ?? ?? Emily Lewis Core Practical 31/12/2006 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Humans as Organisms essays

  1. Marked by a teacher

    In this experiment we are trying to find out how the concentration of caffeine ...

    3 star(s)

    Caffeine molecule My Plan In my investigation I am trying to find out how varying the concentration of caffeine can affect the heart rate of a brine shrimp. To make sure that the practical is a fair test only the concentration of the caffeine will be changed, the caffeine is

  2. The Effect of Caffeine on the Heart Rate of Daphnia.

    I then had 30 seconds to transfer the daphnia to a depression slide and cover it with a cover slip before counting the heart beat for 20 seconds using a clicker counter and multiplying by 3 to obtain a result in bpm.

  1. An experiment to see if caffeine affects heart rate

    If the daphnia were used multiple times in this experiment it would be unfair on the daphnia as the caffeine may be harming them and we would not know.

  2. INVESTIGTING THE EFFECT OF CAFFEINE CONCENTRATION ON

    out systematically to reduce the risk of any random errors (lying equally above or below true value). The following concentration should be used as they are fairly small amounts and so it will be easier to distinguish trends and also so that the concentration does not prove fatal to the Daphnia Concentration (%)

  1. HypothesisI think that the amount of caffeine in the blood will determine the heart ...

    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. Hypothesis I think that the amount of caffeine in the blood will determine the heart rate of the daphnia.

  2. The Pick Up

    As the truck stops, Derek jogs over to the passenger side window. The filthy window lowers as Derrick peers inside. "Excuse me sir, can you give me a lift to a petrol station? I had a breakdown a few miles back, and I am kind of far from home."

  1. Investigating The Effect Of Drugs On the Heart Rate of a Daphnia.

    To make the investigation a fair test I will use the same daphnia all the way through so that the size and the consumption of alcohol is the same in one daphnia. If I was to use different daphnia then I wouldn't be getting accurate results because one daphnia may

  2. The effect of caffeine concentration on the heart rate of Daphnia.

    The heart beats were then counted in ten second stints. This was felt to be a suitable measurement as this meant that the number of heart beats could be multiplied by six to obtain the heart beat per minute. It also allowed for the fact that the hand and the

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work