Valerie designed and conducted an experiment on pothos plants, which are common houseplants. Her hypothesis is that the direction of light will affect the growth pattern of a pothos plant. To test the hypothesis, she sets up two test groups of pothos plants and observes them three weeks later. The table summarizes the test groups and observations. Test Group Growth Conditions Observations 1 Light source is only on the side of the plant Stems and leaves are bent toward the light 2 Light source comes from all directions Stems and leaves are not bent What are the roles of the two test groups in this investigation?

Respuesta :

Answer: The roles of two test groups in the investigating a phenomenon known as  positive phototropism. This phenomenon occurs in the plants that responds to external stimuli (light). In this experiment we can see that the pothos plant is having a positive response in both the cases :

1. When the light source is on one side the stems and leaves are bending towards the light source only on one side

2. On the other hand when the pothos plant is given lights from all the directions the growth of the plant takes place in all the directions equally hence it proves that the plant is showing positive responses in the directions where light is present