Question

How do stomata open and close? Do they use receptor?

Answer 1

Stomata:

1. The many pores found at the lower epidermis of the leaf are called stomata.
2. They can be found in the stem as well.
3. Stomata provide for gas exchange and transpiration.
4. Two guard cells that control the opening and shutting of the stomata surround it.
5. For gaseous exchange and to release water vapor during transpiration, stomata open during the day.
6. The change in the guard cell's turgor pressure causes the stomata to open and close.

Opening and closing of stomata:

1. Due to increased transpiration pull during the day, water is absorbed by the roots and transferred through the xylem to various areas of the plant.
2. Upon receiving this water, the guard cell swells and becomes turgid.
3. The stomatal pore is open as a result.
4. The guard cell shrinks and becomes stiff at night because the roots absorb less water.
5. Consequently, stomatal pores close.
6. The guard cells become hypertonic when the potassium (K) ion concentration rises, allowing more water to enter the cells.
   The stomatal pore opens up during this.
7. This is the opposite of opening since it takes place when the water inside the guard cells is eliminated, causing them to become flaccid. The ions K⁺ leave the cell. The stomatal pore closes as a result.

Stomata use receptors:

1. Photoreceptors are found in guard cells.
2. Numerous processes, including stomatal opening, phototropism, chloroplast movement, etc., are triggered by phytotropin proteins.