BOTANY
PLANT GENETICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A seedling growing towards a sunny window.
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Plant roots growing down into the soil.
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Flowers producing nectar to attract bees.
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A potted plant wilting when it dries out.
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Detailed explanation-1: -Geotropism is a force that affects certain organisms. Which of the following is an example of a plant responding to the external stimulus of gravity? A seedling growing towards a sunny window.
Detailed explanation-2: -Plant roots always grow downward because specialized cells in root caps detect and respond to gravity. This is an example of a tropism. A tropism is a turning toward or away from a stimulus in the environment. Growing toward gravity is called geotropism.
Detailed explanation-3: -Plants also detect and respond to the daily cycle of light and darkness. For example, some plants open their leaves during the day to collect sunlight and then close their leaves at night to prevent water loss. Environmental stimuli that indicate changing seasons trigger other responses.
Detailed explanation-4: -External stimulus. The external stimulus includes touch and pain, vision, smell, taste, sound, and balance (equilibrium). These sensory stimuli are activated by external changes.
Detailed explanation-5: -Smell, sound, etc., are examples of external stimuli and hunger, thirst, etc., are examples of internal stimuli.