Final answer:
Different experimental scenarios suggest that increased light hours generally correlate with increases in plant growth, including factors like final height, flower production, and seed germination. The specific responses can be dependent on the type of light and species of plant. (option a)
Step-by-step explanation:
The effect of light on plant growth can be determined by exposing plants of the same species and initial height to varying hours of light. When considering the scenarios presented:
- Seedlings display heliotropism and continue to show movement even after being put into the dark, suggesting a dependence on light for positional movement.
- An observed difference in size between two similarly planted plants, where one received more sunshine than the other, suggests that light impacts growth.
- In an experimental setup, plants maintained under different light conditions showed a difference in flower formation, indicating that light duration can influence flowering in plants.
- Seed germination can be affected by light, with red light altering the germination rates, which points to light's role in seed development.
- Plants grown under different colored lights would show variable growth based on the photosynthetic efficiency of the particular light color.
From these analyses, we can draw a general conclusion that increased light hours lead to increased final height and other growth factors in plants, while also acknowledging the role of light quality and specific responses such as flowering and seed germination.
Hence, the answer is option a