How Do Plants Respond To Positive Phototropism

Phototropism in Plants

Objective: Observe how plants respond to light and how they respond when there is a limited source of light.

Introduction: Phototropism is the way plants respond to light, which dictates whether the plant will lean towards the light which is positive phototropism, or away from light, which is negative phototropism. Auxin is a plant growth hormone, and when light only hits one side of the plant, the auxins move to the darker side. These hormones then stimulate the cells on the darker side to elongate, resulting in a bend towards sunlight. In my experiment, I am going to research what effect minimal light on a plant has on its orientation. The independent variable is light, and the dependent variable is plant orientation, meaning whether it orients itself in a manner of positive phototropism or negative phototropism.

If the plant has an equal amount of light hitting it from all sides, it should grow straight

This is result of auxin, the growth hormone present in plants. The hormones stimulate elongation on the dark side of the plant, creating a bend towards the light. The bending of the light allows more light to reach more parts of the plant. This is of great importance as light is a vital factor in a plant 's life, including in photosynthesis, the process wherein plants convert carbon dioxide into glucose for themselves and provide us with oxygen. The control group, plants 1 and 2, should grow straight upwards, due to the fact that light is hitting all parts of the plant, meaning auxin is not present more on side than the