2006-09-08 18:03:18 · 7 answers · asked by dave l 1 in Science & Mathematics ➔ Biology
response to sunlight: growth toward sunlight by a plant
In pioneering work in plant tropisms, Charles Darwin in 1880 demonstrated that growing tips of plants bend toward a light source. This phenomenon is known as phototropism. (Darwin also observed that some shade plants turn away from bright light by a negative form of phototropism.) The turning is due to the action of the plant hormone auxin, which causes elongation. On the side of a plant facing the light the auxin is inactivated, and only the side away from the light elongates; hence the plant tends to bend toward the light. As a result of phototropism, plants avoid excessive shading by other plants. Phototropism stimulated by sunlight is called heliotropism.
2006-09-08 18:13:41 · answer #1 · answered by yoyox_34 2 · 0⤊ 0⤋
In simple terms, it's when a plant is able to physically turn so as to face the sun as it travels across the sky during the day.
2006-09-08 18:09:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Growth or orientation of a sessile organism, especially a plant, toward or away from the light of the sun.
2006-09-08 18:05:24 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Flying a helicopter low over a grove of palm trees.
2006-09-08 18:11:09 · answer #4 · answered by goatuscrow 4 · 0⤊ 0⤋
attaction to the sun
2006-09-08 18:04:35 · answer #5 · answered by Bad kitty 2 · 0⤊ 0⤋
look it up gosh its not that hard
2006-09-08 18:04:26 · answer #6 · answered by anna_banana♥LALakers. 3 · 0⤊ 1⤋
www.wikipedia.com
2006-09-08 18:05:04 · answer #7 · answered by Anonymous · 0⤊ 0⤋