Question

A sunflower always bends towards sunlight? write the reason​

Answer 1

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 curvature.

Answer 2

Answer:

Explanation:

1)Phototropism is growth of plant in response to the light. Phototaxis is the movement of plant in response to diffuse stimulus of light. Photonasty is the nastic nondirectional movement in response to the light. Nyctinasty is the nastic movement in response to the onset of darkness. Seismonasty is nastic movement in response to touch. Heliotropism is the seasonal motion of plant parts in response to the direction of the sun. Movement of sunflower towards the direction of sun is heliotropic movement.

2) The sun flower follows the sun because of the plant hormones called auxins. Auxins make the plant grow faster and sunlight destroys auxin. So, the shaded side of the stalk grows faster than the side getting the bright sun, so it bends toward the sun. Also, direct light slows cell elongation, so the shaded part (cells) grow (elongate) more rapidly than the side with bright light, thus moving the sunflower head as if it were following the sun.

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