Biology – Control and coordination in plants | e-Consult
Control and coordination in plants (1 questions)
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Here's a description of the expected observations in each dish and the underlying reasons:
| Dish | Expected Observations | Explanation |
| A (Control - Distilled Water) | Minimal germination. Seeds may remain dormant, or germination may be very slow and incomplete. | Distilled water lacks the signal (gibberellin) required to overcome seed dormancy. ABA levels are likely high, inhibiting germination. The seeds are not stimulated to mobilize stored reserves. |
| B (Low Concentration of Gibberellin) | Increased germination compared to the control. A noticeable number of seeds will germinate, but the rate will be slower than in Dish C. | The low concentration of GA partially overcomes the inhibitory effects of ABA. The expression of genes involved in germination is stimulated, but not to the same extent as with a higher concentration. Starch mobilization is initiated, but at a slower rate. |
| C (High Concentration of Gibberellin) | Very high germination rate. Nearly all seeds will germinate rapidly. The radicle will emerge quickly, and the hypocotyl may elongate significantly. | The high concentration of GA strongly overcomes the inhibitory effects of ABA. The expression of genes involved in germination is strongly upregulated. Starch mobilization is rapidly accelerated, providing ample energy for growth. Cell elongation is stimulated, leading to a faster emergence of the seedling. However, excessively high concentrations could potentially lead to abnormal growth or other negative effects. |
This experiment demonstrates the concentration-dependent effect of gibberellin on barley germination. The control provides a baseline for comparison, while the low and high concentrations illustrate the range of effects that GA can have on the germination process. It's important to note that the optimal concentration is likely somewhere between the low and high concentrations tested.