The Effects of Caffeine on Plant Germination By: Erin Chandler

Question How will different amounts of caffeine exposure effect the growth and germination of radish seeds?

Background Information #1 drug in America Caffeine is better known as trimethylxanthine The chemical formula of trimethylxanthine is C8H10N4O2 Naturally made in some plants Used in sports Caffeine and the brain Growth hormone or inhibitor? Raphannus Sativus Growing conditions Process of germination

Hypothesis If seeds are exposed to caffeine solutions of various concentrations, then those exposed to the highest concentration will have higher germination rates and longer root lengths then those exposed to solutions with lower caffeine concentration.

Materials bleach dropper distilled water gloves 5 beakers 200mg caffeine pill mortar and pestle radish seeds 20 Petri dishes 12 pieces of filter paper

Procedure Wear gloves as seeds were soaked in a bleach/water solution and rinse Label beakers 1-5 and fill beaker 1 with 100 mL of water Crush caffeine pill and put it in beaker 2 with 100 mL of water, stir Take 10 mL from beaker 2 and add to beaker 3 along with 90 mL of water, stir Take 10 mL from beaker 3 and add it to beaker 4 along with 90 mL of water, stir Take 10 mL from beaker 4 and add it to beaker 5 along with 90 mL of water, stir Label Petri dishes according to caffeine concentration and then trials 1-4 Soak filter paper in 3 mL of solution and place in appropriate Petri dish Put 10 radish seeds in each Petri dish Put Petri dishes in a dark enclosed area for a certain amount of time

Variables Control: seeds exposed to distilled water Independent Variable: amount of caffeine in each solution Dependent Variables: amount of seeds that germinate, and root lengths Constants: amount of solution on filter paper, temperature, number of seeds in each Petri dish, temperature of water

Data Seeds Germinated

Data (2)

Discussion The data in this experiment showed that, the caffeine did cause a change in the way the seeds germinated and grew The solution with the most caffeine had the least amount of seeds germinated and in the control the most amount of seeds germinated The t test showed that all data can be interpreted because all results are lower then .05, the conclusion that can be drawn according to the t test is that caffeine has a major effect on the plant’s germination The hypothesis was not supported by the results generated in this experiment These results show how caffeine has a negative effect on the seeds, and that stimulants do not help the growth of plants Caffeine is the number one drug used in America, it can be concluded that caffeine most likely does not have a positive effect on the millions of people that consume it every day

Changes and Further Experimentation If this experiment were to be conducted again, more trials would have been very beneficial It also would have helped to put the Petri dishes in plastic bags so that the seeds did not dry out. This would have allowed for more growing time for the seeds which would result in more data and more accurate results. Also, testing even more amounts of caffeine on the seeds may have shown more significant results so that better conclusions could have been drawn If a person wanted to take this experiment further they could have experimented with different kinds of seeds, put the seeds in different environments or tested the seeds with other drugs similar to caffeine

Thank You Brian, M., & Bryant, C. W. (n.d.). How Caffeine Works. Retrieved October 6, 2010, from Discovery Health website: http://health.howstuffworks.com/      wellness/drugs-alcohol/caffeine1.html Caffeine. (n.d.). Retrieved January 30, 2011, from chemBlink website:      http://www.chemblink.com/products/58-08-2.htm Enblogopedia. (n.d.). What are the effects of caffeine? Retrieved September 5, 2010, from Enblogopedia website: http://www.mycaffeineaddiction.com/      the-effect-of-caffeine-on-plant-growth/ Greenaway, T. (2001). Plant Life. Austin, TX: Raintree Steck-Vaughn Publishers.Growing radish from seed. (2000). Retrieved September 5, 2010, from GardenAction  website: http://www.gardenaction.co.uk/fruit_veg_diary/      fruit_veg_mini_project_june_1b_radish.asp Olympic Gold? A New Effect of Caffeine Boosts Performance. (2010, June 30). Science Daily. Retrieved from http://www.sciencedaily.com/releases/2010/      06/100629193123.htm Reid, T. (n.d.). Caffeine-What's the Buzz? National Geographic. Retrieved from      http://science.nationalgeographic.com/science/health-and-human-body/human-body/caffeine-buzz.html#page=8