Part one of term paper
Involvement of K+ in Leaf Movements During Suntracking Introduction Many plants orient their leaves in response to directional light signals. Heliotropic movements, or movements that are affected by the sun, are common among plants belonging to the families Malvaceae, Fabaceae, Nyctaginaceae, and Oxalidaceae. The leaves of many plants, inclu ...

Part two of term paper
... of photosynthetically active radiation (PAR). In some plants, but not all, his response occurs particularly during the morning and late afternoon, when the light is coming at more of an angle and the water stress is not as severe (Donahue and Vogelmann). Under these conditions the lamina of the leaf is within less than 15° from the normal to the sun. Many plants that exhibit diaheliotropic movements also show paraheliotropic response as well. Paraheliotropism minimizes water loss by reducin ...