Final answer:
In the 0% light treatment, plants grow tall and spindly, similar to their growth in darkness, due to the absence of light required for photomorphogenesis and other light-dependent processes like phototropism.
Step-by-step explanation:
In the 0% light treatment, plants typically exhibit behaviors like those seen in darkness. This means that a plant will likely grow tall and spindly due to the lack of light stimulus for photomorphogenesis. Plants need light to trigger the photoreceptors such as phytochrome and phototropin, which regulate processes like germination, flowering, and directional growth towards light (phototropism). Without light, these processes cannot be activated, and the plant may enter a dormant state to conserve energy until light becomes available again. This can also lead to the switching to anaerobic metabolism in some plants. Additionally, the relative concentrations of chlorophyll pigments can change in plants that are adapted to growing in the shade.