FORESTRY
PLANT AND WOOD ANATOMY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The roots need water.
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Sunlight hits the plants.
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Gravity pulls on the roots.
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There is plant food in the soil.
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Detailed explanation-1: -After several tries, he found that the roots always grew down. Nothing he or his teacher did made the roots grow up. What keeps the roots from growing up? The roots need water.
Detailed explanation-2: -Plants have the uncanny ability to send their roots down and their shoots up, even if the seedlings are rotated. The plants are sensing gravity.
Detailed explanation-3: -The roots grown downward in the direction of gravity, which is positive gravitropism, and the shoot grows upward away from gravity, which is negative gravitropism. The reason plants know which way to grow in response to gravity is due to amyloplasts in the plants.
Detailed explanation-4: -Plants respond directly to Earth’s gravitational attraction, and also to light. Stems grow upward, or away from the center of Earth, and towards light. Roots grow downward, or towards the center of Earth, and away from light. These responses to external stimuli are called tropisms.