|One of my young students wants to study the effect of different liquids (water, vinegar 5% acidity, salt water 4 tsp.per liter, juice and coca cola) on the germination of bean seeds. He has sown them in separate jars in paper towels soaked with the various liquids and is observing the effect, looking for which sprout, how soon, any differences, etc.They are all kept moist and in the same location with fair sunlight. Should there be any difference if the seeds aren't killed by the liquid? Don't the seeds live off the food within? Any thoughts or guidance would be most helpful.|
|It's great to encourage students to design their own experiments and learn to observe!
In their dry state, seeds are in a sort of "suspended animation". Then, once they are exposed to moisture, they begin to swell and the tiny embryo within starts to grow. Seeds do have food storage structures called cotyledons. In fact most of the bean seed is made up of these storage structures. This provides stored food so the plant can sprout and develop its first leaves, when it can then begin manufacturing its own food through photosynthesis.
I honestly don't know if he will find any differences in the liquids. Some liquids may be more readily absorbed by the seeds than others. Some may damage the tiny embryo and emerging roots and shoots.
I suggest you keep the seeds out of sunlight until they germinate, because they don't need light until they are growing, and too much light and heat will quickly dry them out.
I hope this helps!