A student investigated the effect of radiation on the germination of bean seeds. He thought that exposure to radiation would limit the seeds ability to germinate (grow) much like ultra-violet light causing skin cancer. Three hundred seeds were soaked in water for one hour. They were then divided into three groups of 100 beans each. One group was placed in a microwave*oven on high for three seconds. Another group was microwaved on high for six seconds. The last group was not microwaved. The seeds were then planted in three separate flats and given the same amount of water. The flats were placed in a location with a constant temperature of approximately 27 degrees Celsius. Each day for two weeks the number of seeds that germinated each group was recorded. The results of his experiment are noted below:
Length of exposure
3 seconds of radiation
6 seconds of radiation
No radiation
# Germinating seeds
54 seeds
26 seeds
88 seeds
*Note: microwaving the seeds exposes them to radiation Complete each of the following:
Identify the student's hypothesis: exposure to radiation will limit seeds ability to germinate
Identify the independent variable: the amount of radiation seeds are exposed to
Identify the dependent variable: seeds ability to germinate
Identify the other variables the student needs to consider/control during this experiment: all be the same type of bean seed, same amount of water, temperature of water, seed storage, size of the planting flat/pot, seed conditions, same climate, type of soil, amount of soil, brand of beans,
Identify the control group in this experiment: group of seeds not microwaved (exposed to radiation)
Identify the experimental group: seeds that are microwaved one group for 3 sec and one group for 6 sec
What conclusions might the student draw from this data? seeds without radiation germinate better than the seeds that were exposed to radiation (hypothesis was correct) as 88/100 seeds germinated with zero radiation while 54/100 and 26/100 germinated with 3 seconds and 6 seconds. An increase in radiation caused a decrease in germination.
What recommendations might you suggest for further study or for improvement? ensure all of the variables identified in #4 above are held constant not just soaking time, amount of water, and temperature of growing environment; try the experiment on another type of seed instead of bean seed (pumpkin, marigold, radish, etc) to make sure it isn't just something that happens with bean seeds.
A student investigated the effect of radiation on the germination of bean seeds. He thought that exposure to radiation would limit the seeds ability to germinate (grow) much like ultra-violet light causing skin cancer. Three hundred seeds were soaked in water for one hour. They were then divided into three groups of 100 beans each. One group was placed in a microwave* oven on high for three seconds. Another group was microwaved on high for six seconds. The last group was not microwaved. The seeds were then planted in three separate flats and given the same amount of water. The flats were placed in a location with a constant temperature of approximately 27 degrees Celsius. Each day for two weeks the number of seeds that germinated each group was recorded. The results of his experiment are noted below:
Complete each of the following: