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Unformatted text preview: 2 for cell respiration, there are mechanisms in plants for gas exchange besides stomata. Oxygen produced during photosynthesis does not diffuse to all parts of the plant. Substances will diffuse along the easiest route and gradient, and much oxygen is lost through stomata. However, plants have a number of ways to get oxygen to cells. Oxygen Routes Primary growth stems have stomata in the stem epidermis. Secondary growth stems have lenticels in the cork (bark) Roots obtain oxygen by diffusion through the root epidermis, which is not cutinized. Oxygen competes with water for essential soil spaces, and water saturated soils may cause the roots to suffocate from lack of oxygen. Submerged aquatic plants must obtain both CO 2 and O 2 from gases dissolved in water, and growth rates are generally lower, since amounts of O 2 and CO 2 are less in water than in the atmosphere....
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This note was uploaded on 01/08/2012 for the course BIO 213 taught by Professor Makina during the Fall '09 term at SUNY Stony Brook.
- Fall '09