Stomata and guard cells are two related structures found on the surfaces of plant leaves and stems, but they serve different functions. Here’s the difference between stomata and guard cells:
– Stomata (singular: stoma) are small pores or openings found on the surfaces of plant leaves, stems, and other aerial parts.
– Stomata play a crucial role in gas exchange, allowing plants to take in carbon dioxide (CO2) for photosynthesis and release oxygen (O2) and water vapor (transpiration) into the atmosphere.
– Each stoma consists of two specialized cells called guard cells that surround the pore.
– Guard cells are specialized cells that flank the stomatal pore and regulate its opening and closing.
– Guard cells are kidney-shaped and have thicker walls on one side and thinner walls on the other.
– When guard cells take up water, they become turgid, causing them to curve and create an opening (stoma) between them.
– The opening and closing of guard cells are controlled by changes in their turgor pressure, which is influenced by various factors, including light, temperature, humidity, and the plant’s water status.
– When the guard cells lose water, they become flaccid, causing the stomatal pore to close and prevent excessive water loss through transpiration.
In summary, stomata are the small pores or openings on the plant’s surface, while guard cells are the specialized cells that surround and regulate the opening and closing of stomata. Stomata allow for gas exchange and transpiration, while guard cells control the opening and closing of stomata to regulate the balance between gas exchange and water loss in plants.