Why do sunflowers turn with the sun and bloom towards it?

1. Causes

1. As early as the end of the 18th century, a reasonable explanation for this problem was given. The reason is that plants are phototropic and it is caused by a natural reaction in the body.

2. The main reason is due to an element in the body itself - chlorophyll. This substance will cause the sunflower to slowly turn around under the stimulation of the sun and move in the direction of the sun. Because the density of this material on the side that does not see the light is lower, and the density of this material on the side that sees the light is higher, so after the sun rises from the east in the morning, it will gradually begin to move, and after the sun sets in the evening, it will return to its original position. But usually, it stops rotating after it blooms, and always faces the direction where the sun rises.

3. This phenomenon is also caused by the factor of the earth's gravity. After the sun sets, the sky becomes dark. The lack of light causes the hormones in the body to drop rapidly. The originally bent branches become upright, and then they return to their original state and grow. They repeat this growth cycle, changing their angles according to the direction of the sun.