Question

Why sunflower's always turns towards the sun?

Answer 1

Heliotropism. Sunflowers turn their faces toward the sun as they track it across the sky -- an activity known as heliotropism, or solar tracking. Special motor cells at the bases of the flower buds shrink or enlarge as they absorb water, which moves their faces toward the sun.

Answer 2

Answer:

Facing of sunflower towards the sun is known as phototropic movement. This is due to presence of auxin, a growth harmone in the stem.

The higher concentration of auxin in the shaded side causes that side to grow faster, resulting in a positive phototropic curvatur