Why are the stomata on the upper surface of the leaf Unlike most plants where the stomata are present on the lower surface?
Stomata in most plants are more numerous on the lower surface of a leaf instead of being on the upper surface because the presence of stomata on lower surface will prevent excessive transpiration from taking place.
How does the upper surface of a leaf differ from the lower surface?
The main difference between upper epidermis and lower epidermis is that upper epidermis possesses a cuticle layer whereas lower epidermis possesses a large number of stomata.
Are stomata equally distributed throughout the upper and lower epidermis of the leaf?
Stomata equally distributed on the upper and lower surface of the leaf. Stomata present only on the lower surface of the leaf.
Why are there different amounts of stomata in different areas of the leaf?
The evaporation of water from the leaf is called transpiration. The number of stomata on leaf surfaces varies widely among different species of plants. Researchers have evidence which indicates that stomata densities change in response to changing atmospheric levels of carbon dioxide.
Which leaf has the most stomata?
Explanation: All surfaces of the leaf have some amount of stomata for regulating gas exchange for photosynthesis. However, the lower epidermis (the underside of the leaf) has more, because it is more often in the shade and so it is cooler, which means evaporation won’t take place as much.
Why is stomata at the bottom of the leaf?
Stomata are tiny holes found in the underside of leaves. They allow water vapour and oxygen out of the leaf and carbon dioxide into the leaf. Plants growing in drier conditions tend to have small numbers of tiny stomata and only on their lower leaf surface, to save water loss.
What type of plant has the most stomata?
Dicotyledons
Where do we find most of the stomata?
leaves
What makes stomata open?
Stomata are composed of two guard cells. These cells have walls that are thicker on the inner side than on the outer side. This unequal thickening of the paired guard cells causes the stomata to open when they take up water and close when they lose water.
What controls the opening and closing of stomata?
Control of the size of the stomatal aperture optimizes the efficiency of water use through dynamic changes in the turgor of the guard cells. The opening and closing of stomata is regulated by the integration of environmental signals and endogenous hormonal stimuli.
How are stomata open and closed?
The role of stomata Each stoma can be open or closed, depending on how turgid its guard cells are. In the light, the guard cells absorb water by osmosis , become turgid and the stoma opens. In the dark, the guard cells lose water, become flaccid and the stoma closes.
How do stomata open and close explain with diagram?
The opening and closing depends upon the turgor pressure in the guard cells. The swelling of guard cells due to absorption of water causes opening of stomatal pores while shrinking of guard cells closes the pores. Opening and closing of stomata occurs due to turgor changes in guard cells.
How do stomata open and close potassium?
When the guard cells take in potassium ions, water diffuses into the cells by osmosis. This causes the guard cells to bend away from each other, thereby opening the stomata. Conversely, when guard cells lose potassium ions, water diffuses out of the cells by osmosis.
What importance is potassium in the opening and closing of stomata?
K+ ions move out of the cell. This causes the stomatal pore to close. This occurs in the absence of light or when rates of photosynthesis are low. In this condition the stomatal pore is closed.
Which hormone is responsible for opening of stomata?
Cytokinins