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Daphnia experimentation

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  • Essay length: 2680 words
  • Submitted: 11/02/2008
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AS and A Level Energy, Respiration & the Environment

The first 200 words of this essay...

The effect of Caffeine on the heart rate

Aim:

To investigate the effect of caffeine on the heart rate of Daphnia (water fleas).

Background Knowledge:

Daphnia are tiny water fleas with an average size of less than 3mm. Daphnia are translucent invertebrates (have no backbone) and their outer body is made up of a hard shell which protects the whole body except for the head. Daphnia's are found in ponds, lakes, and calm streams where the temperature is between 21-24°C (68-71°F). Daphnia reproduce rapidly. Up to 13 billion related offspring can occur within 60 days for one Daphnia. In winter the eggs are thick-shelled and thin shelled in the summer. In warmer temperatures the eggs will hatch female, and in colder temperatures the eggs will be male.

Daphnia's will be used to experiment the on as although they are tiny in size their heart beat can be examined through a microscope because of their transparency.

Caffeine is produced by plants as an insecticide. Cocoa in South America, coffee in Africa and tea in Asia has all been used for hundreds of years to produce "pick me up" drinks

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