Question

You place a flower near a window so it has a source of sunlight. A few hours later, you notice the flower is now pointing toward the window, even though it was formerly facing the room. What is this process of growing toward the sunlight an example of?

1) Phototropism
2) Geotropism
3) Hydrotropism
4) Thigmotropism

Answer 1

The flower's movement toward the window is an example of phototropism, which is the response of a plant to grow towards a light source. It's controlled by hormones that cause cells to elongate on the darker side of the stem, resulting in the bending of the plant toward the light.

Step-by-step explanation:

The process of a flower growing toward sunlight is an example of phototropism, which is a type of plant tropism specifically in response to light. Plants exhibit this tropism when their leaves and stems bend toward the light source to maximize the amount of light they receive for photosynthesis. This growth pattern is controlled by plant hormones called auxins, which promote cell elongation on the side of the plant that is farther from the light, causing the plant to bend toward the light source. Since the flower is bending toward the window to access more sunlight, it demonstrates positive phototropism.

In contrast, geotropism refers to plant growth in response to gravity, hydrotropism is growth towards water, and thigmotropism is the plant's growth response to touch. Since the flower in the question is turning toward the light source, it is not displaying geotropism, hydrotropism, or thigmotropism, but rather phototropism.