Question

What is the role of stomato and what is the role ofepidermis

Answer 1

Function The gas exchange that occurs when stomata are open facilitates photosynthesis. Photosynthesis is the process by which plants convert sunlight into usable energy. During photosynthesis, carbon dioxide is taken in from the atmosphere through the stomata and oxygen is released as a waste product. Both photosynthesis and the gas exchange that powers it are essential to the plant's survival. An unfortunate side effect of the stomata opening is that it allows for water loss. Unlike you and me, plants do not need to sweat to cool off and prefer to keep their water inside; however, because the gas exchange of photosynthesis is so vital, some water loss through stomata is necessary. This process of plant water loss is called transpiration. Although transpiration cannot be avoided, plants can minimize their water loss by controlling how wide their stomata are open, as well as what time of day they are open. Opening stomata when the surrounding air is more humid means that less water will evaporate from the plant leaves, but opening them when temperatures are warmer means more evaporation will occur. Likewise, if a plant is already dehydrated, it may close its stomata to prevent further water loss. The epidermis cells (from the Greek , meaning "over-skin") is a single-layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions, it protects against water loss, regulates gas exchange, secretes metabolic compounds, and (especially in roots) absorbs water and mineral nutrients. The epidermis of most leaves shows dorsoventral anatomy: the upper (adaxial) and lower (abaxial) surfaces have somewhat different construction and may serve different functions. Woody stems and some other stem structures which produce a secondary covering called the periderm that replaces the epidermis as the protective covering.