Question

3. Now examine a prepared slide of a Psilotren stem cross Section Notice the epidermis with its well-developed cuticle. Stomata are present here as well. The cortex is relatively large and has three regions. Beneath the epidermis is a region of parenchyma cells that contain chloroplasts (chlorenchyma). Adjacent to the chloren- chyma is typically a zone of sclerenchyma cells that give the stem support. The innermost portion of the cortex consists of another region of parenchyma cells, which are modified for food storage. In the center of the stem is the single bundle of vascular tissue. The xylem is found in the very center and is surrounded by the phloem. This type of stele is referred to as a proto- stele. At the junction between the stele and the cortex is an endodermis. A Casparian strip should be easily seen here. 4. Label the cuticle, epidermis, guard cells and stoma, chlorenchyma tissue, sclerenchyma tissue, food storage region of the cortex, endodermis, xylem, and phloem seen in Figure 11.3. FIGURE 11.2 Psilotum branches with sporangia, 1X. FIGURE 11.3 Psilotum, cross section of an arterial stem, 75x. EXERCISE 11 * Primitive Vascular Plants 115

label 11.2 and 11.3

Answer 1

Figure 11.2 Ligule Sporangium Dichotomous branch Stem Note: According to Chegg's guidelines, you have to send just one question. Please, send each question separate so all experts can answer each of your questions. Thank you!.