Stoma/stomata/stomate

The pathway of least resistance for gases to cross an epidermis—and thus to enter or to exit from a leaf—is through the adjustable space between a pair of guard cells (Fig. 1-2). This pore, and its two surrounding guard cells, is called a stoma or stomate (plural stomata and stomates, respectively). When they are open, the stomatal pores allow for the entry of CO2 into the leaf and for the exit of photosynthetically produced O2. The inevitable loss of water vapor by transpiration also occurs mainly through the stomatal pores, as we will discuss in Chapter 8 (Section 8.1B). Stomata thus serve... 

Stomat al Cham bei.—The interceUular-air-space directly beneath the stoma. Stri ate.—Marked with fine longitudinal lines or grooves. 

Stomatal resistance is a critical factor affecting pollutant uptake. The resistance is determined by stomatal number, size, anatomical characteristics, and the size of the stomatal aperture. Little or no uptake occurs when the stoma is closed. Stomatal opening is regulated by internal C02 content, temperature, humidity, light, water availability, and nutrient status, particularly potassium. Research shows that K+ ions in the guard cells regulate the guard... 

A minute pore in the epidermis of plant leaves or stems. Stoma, which are bordered by guard cells that regulate the size of the opening, function in gas exchange between the plant and the external environment. The stomatal apparatus or stomate consists of the stoma plus guard cells, stratification... 

Fig. 5.29. Transmission electron micrograph of a stoma on stem of Opuntia ficus-indica. V, vacuoles m, mitochondria n, nucleus p, plastids po, stomatal pore (slightly open) sn, nucleus of a subsidiary cell (from Thomson and De Journett, 1970 a, by permission)...

The cell structure of a typical leaf is shown in Figure 3.5a and Figure 3.5b. Transport takes place mainly through openings termed stomatal pores (stoma Greek for mouth), which are concentrated at the underside of the leaf. Stomata... 

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