Two petri dishes of radish seeds are prepared as follows: a disk of absorbent, but otherwise inert, filter paper is placed in the bottom of each dish and 5 ml of distilled water are added to each disk, then two grams of dry radish seeds are spread over each moist disk. one dish is put in a dark cupboard and the other is put on a sunny windowsill. the investigator checks the dishes daily and adds water equally as needed. seeds in both treatments germinate within 2 days. at the end of 10 days, the plant material on each petri plate is dried and weighed. the results are: