Guard cells are found in leaves .They surround and protect stomata....!!

Guard Cells in Plants

Guard cells are specialized cells found in the epidermis of plant leaves and stems. They play a crucial role in regulating the process of transpiration, which is the loss of water vapor from the plant's surface. Guard cells are responsible for controlling the opening and closing of stomata, which are small pores on the plant's surface that allow for gas exchange.

Structure of Guard Cells

Guard cells are kidney-shaped cells that are typically found in pairs surrounding the stomata. They have a thicker inner wall and a thinner outer wall. The inner wall is elastic and can stretch or contract, allowing the guard cells to change shape and control the opening and closing of the stomata.

Function of Guard Cells

Guard cells regulate the opening and closing of stomata, which is vital for the survival and growth of plants. The main functions of guard cells include:

1. Controlling Gas Exchange: Guard cells control the opening and closing of stomata to regulate the exchange of gases such as carbon dioxide and oxygen. During photosynthesis, when light is available, guard cells take up water and become turgid, causing the stomata to open and allowing for the entry of carbon dioxide. Conversely, when light is limited or during hot and dry conditions, guard cells lose water and become flaccid, resulting in stomatal closure to prevent excessive water loss.

2. Regulating Transpiration: Guard cells also play a significant role in regulating the process of transpiration. Transpiration is the loss of water vapor from the plant's surface through the stomata. By controlling the opening and closing of stomata, guard cells help plants conserve water during periods of drought or water scarcity.

3. Facilitating Photosynthesis: The opening and closing of stomata by guard cells also influence the rate of photosynthesis. By allowing the entry of carbon dioxide into the leaf, guard cells ensure an adequate supply of this essential gas for the process of photosynthesis, which is crucial for the production of glucose and other organic compounds necessary for plant growth.

4. Responding to Environmental Factors: Guard cells are capable of sensing and responding to various environmental factors such as light intensity, temperature, humidity, and carbon dioxide concentration. These responses allow plants to adapt and optimize their gas exchange and water regulation according to changing environmental conditions.

In conclusion, guard cells are specialized cells found in the epidermis of plant leaves and stems. They regulate the opening and closing of stomata, control gas exchange, regulate transpiration, facilitate photosynthesis, and respond to environmental factors. Guard cells are essential for the overall health and survival of plants, allowing them to efficiently utilize resources and adapt to changing conditions.