Does light intensity have an effect on stem elongation?
Background information for Mom: When seeds are germinated in the dark, the stems that grow from the embryo are very elongated and white to light yellow in color. Stems in this condition are referred to as etiolated. Plants grown in dim light tend to be long and spindly, but stems that develop in bright light tend to be stout. Your daughter could examine the effects of light intensity on stem elongation. A possible set-up would be to use fluorescent lights which would avoid the heat problems associated with incandescent lights. You can get shop lights at a hardware or discount department store pretty inexpensively, if you don’t have lights that will do. You could help your daughter figure out the experimental design by asking her the following questions. If you ask the question “does light intensity have an effect on stem elongation,” how could you state that as a hypothesis? Hint: Light intensity has an effect on the elongation of growing plant stems. Another way to state this is by us
