Question
Draw the experimental set-up of geotropic movement and label it.
Answer
Experiment geotropism
- Materials required: A few germinating seeds, and a moist substance (moist cotton).
- Procedure:
- Place the germinating seeds in a horizontal position over the moist substance (moist cotton).
- Keep the setup in a dark chamber to avoid the influence of light.
- Observation:
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- After some days, the tip of the radicle (the embryonic root) will bend downwards, showing positive geotropism of the root.
- The plumule (the embryonic shoot) moves in a direction vertically upwards, showing negative geotropism of the stem.
Inference:
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- Stem bending away from the gravitational pull shows negative geotropism, whereas, the root shows positive geotropism by moving towards the external stimulus.
- The movement of roots and stems in response to gravity is essential for plants to grow upright and absorb nutrients and water from the soil.
