The correct answer is option (d) They allow the exchange of gases between cells in the leaf and the external environment.
Stomata are the tiny openings present in the epidermis (outer layer of cells) of the leaf. They have a pore which is guarded by the guard cells which controls the opening and closing of the stomata. Air enters and exits through the stomata.
The main funtion of stomata is to facilitate the gaseous exchange. The gas exchange that occurs when the stomata are open helps in the process of photosynthesis. During photosynthesis, carbon dioxide is taken in from the atmosphere and oxygen is released as a by-product of photosynthesis. The glucose produced is converted into the starch and stored in the leaves.
Also, water vapour diffuses through the stomata into the atmosphere by a process called the transpiration.
Thus, stomata are the structures that are mainly involved in the gaseous exchange between the cells of the leaf and the atmosphere.
One result of a loss of ground water would be that the freshwater on earth is 98 percent stored in the ground, therefore we would lose 98 percent of the very little amounts of freshwater we have
Answer:
Explanation:
Approximately 70% of Earth's surface is covered in ocean water. When water at the ocean's surface is heated by the Sun it gains energy. With enough energy, the molecules of liquid water change into water vapor and move into the air. This process is called evaporation.
Progesterone and estrogens are thought responsible for the release (and prevention of release) of an egg during ovulation
Answer:
Devices used to convert thermal energy to mechanical energy are called heat engines.
The answer is heat engines.
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