fototropisen

Fototropism is a growth response in plants where the direction of growth is influenced by light. This phenomenon is a type of tropism, which is a directional growth response to an environmental stimulus. In fototropism, the stimulus is light, and the response is typically a curvature or bending of the plant towards or away from the light source.

There are two main types of fototropism: positive and negative. Positive fototropism occurs when a plant grows towards the light source. This is commonly observed in stems and leaves, which tend to bend towards the sun to maximize light exposure. Negative fototropism, on the other hand, occurs when a plant grows away from the light source. This is seen in roots, which grow away from the light to search for water and nutrients in the soil.

Fototropism is mediated by the plant hormone auxin, which is produced in the tips of plant shoots and roots. Auxin causes cells on the shaded side of the plant to grow more rapidly than those on the lit side, leading to the characteristic curvature. The process is dynamic and can be reversed if the light source is moved.

Fototropism is an important adaptation for plants, allowing them to optimize their exposure to light for photosynthesis and growth. It is a fundamental aspect of plant biology and has been studied extensively to understand the mechanisms of plant growth and development.