Feature: 1. This model is suitable for teaching visual aids used in the construction of monocotyledonous stems in secondary school biology teaching. 2. PVC material production, light, strong, not easy to break. 3. The structure is simple, easy to operate and clean. 4. The arrangement, morphological structure, coloring, and differentiation of the three organizational systems are obvious. 5. The cells of the basic tissue are parenchyma cells, and their arrangement gradually increases from the outside to the inside. 6. The catheter is V-shaped, the larger one on both sides is a perforated catheter, and the tip end is a ring and a threaded catheter; the vascular bundle is small and many on the edge, and the inner surface is large and small. Specification: Item Type:Stem Structure Model Structure: 1. The model is taken from the corn stalk and the model is cross-cut. Take the cross section 1/0 and remove the central part. 2, showing the epidermis, vascular bundles, basic organization. 2.1 The epidermis shows the stomata, and the epidermis shows the mechanical structure composed of thick-walled cells. 2.2 vascular bundles show vascular bundle sheaths, native phloem, companion and screen, perforated catheters, rings, threaded catheters, and intercellular channels. 2.3 Specimen tissue shows parenchyma cells and interstitial spaces. 3. The ring profile, the spiral screen, the corrugated conduit and the screen tube are shown on the longitudinal section, and the screen and the structure show the structure of various types of cells such as thick wall and thin wall. Package List: 1 x Plant Stem Model