Try this experiment to teach plant reproduction. Place a moist paper towel in a plastic bag. Spread a few fast-sprouting seeds on the paper towel, such as radish, lettuce or carrot seeds. Seal the bag and tape it in a sunny window. Mist it every day to keep it moist. In 5 to 7 days, most of the seeds will begin to sprout. Make a chart detailing which seeds sprout the fastest, and note the differences in leaves and growth.