where is the mesophyll located in a plant
Vascular tissue In leaves, the vascular bundles are located among the spongy mesophyll. The xylem is oriented toward the adaxial surface of the leaf (usually the upper side), and phloem is oriented toward the abaxial surface of the leaf. This is why aphids are typically found on the underside of the leaves rather than on the top, since the phloem transports sugars manufactured by the plant and they are closer to the lower surface.[citation needed]
Pericycle Although it is composed of non-vascular parenchyma cells, it is still considered part of the vascular cylinder because it arises from the procambium as do the vascular tissues it surrounds.
Pennisetum As currently envisioned, Pennisetum is a genus of 80 to 140 species.[7][10][11][13] The various species are native to Africa, Asia, Australia, and Latin America, with some of them widely naturalized in Europe and North America, as well as on various oceanic islands.[2]
Lysosome By scientific convention, the term lysosome is applied to those vesicular organelles only in animals, and vacuoles to plants, fungi and algae. Discoveries in plant cells since the 1970s started to challenge this definition. Plant vacuoles are found to be much more diverse in structure and function than previously thought.[39][40] Some vacuoles contain their own hydrolytic enzymes and perform the classic lysosomal activity, which is autophagy.[41][42][43] These vacuoles are therefore seen as fulfilling the role of the animal lysosome. Based on de Duve's description that "only when considered as part of a system involved directly or indirectly in intracellular digestion does the term lysosome describe a physiological unit", some botanists strongly argued that these vacuoles are lysosomes.[44] However, this is not universally accepted as the vacuoles are strictly not similar to lysosomes, such as in their specific enzymes and lack of phagocytic functions.[45] Vacuoles do not have catabolic activity and do not undergo exocytosis as lysosomes do.[46]