The closure of lid of pitcher in a pitcher plant, is due to [1995]a)tu...
Pitcher plant is an insectivorous plant which catches insects. The paratonic movements are induced in response to an external stimulus caused by insects due to which lids close and the insects are trapped inside the pitcher.
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The closure of lid of pitcher in a pitcher plant, is due to [1995]a)tu...
The leaf lamina and apex of pitcher plant form pitcher and lid respectively. The coloured lid and nectar attract the insects which are then drowned into acidic fluid of pitcher present at it bottom. Sitting of insects stimulates the closing of lid of pitcher which makes it an induced/paratonic movement. The vital movements of plant parts which are induced by any external factor (light, temperature, water etc) are known as induced or paratonic movements as opposed to the autonomic/spontaneous movements
The closure of lid of pitcher in a pitcher plant, is due to [1995]a)tu...
Paratonic movement in the closure of lid of pitcher in a pitcher plant
Paratonic movement is the process where the movement of plant parts is not in response to external stimuli but due to internal factors such as changes in turgor pressure. In the case of the closure of the lid of a pitcher plant, paratonic movement plays a crucial role.
Role of turgor pressure
- Turgor pressure is the pressure exerted by the fluid content inside the cells against the cell wall.
- In the pitcher plant, when the lid of the pitcher is open, the cells in the lid region have higher turgor pressure compared to the surrounding cells.
- This higher turgor pressure keeps the lid open and allows insects to enter the pitcher.
Changes in turgor pressure
- However, when an insect enters the pitcher and triggers the sensory hairs on the lid, the cells in the lid region undergo a rapid loss of water.
- This loss of water leads to a decrease in turgor pressure in the lid cells, causing them to shrink.
- As a result, the lid of the pitcher closes due to the decreased turgor pressure in the lid cells.
Conclusion
In conclusion, the closure of the lid of a pitcher plant is a result of paratonic movement, where changes in turgor pressure within the cells of the lid region lead to the closure of the lid. This mechanism allows the pitcher plant to trap and digest insects for nutrients.
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