Final answer:
Cells with thick cell walls and large hollow centers preferentially stained with a lignin-binding dye likely belong to the xylem. Parenchyma cells comprise the cortex and pith of the stem, which are involved in various plant functions, and are examples of simple tissues because they consist of one cell type.
Step-by-step explanation:
When observing a stem section stained with a dye that binds lignin, if you notice cells with thick cell walls and large hollow centers that are preferentially stained, these cells are indicative of the xylem. The xylem is a type of vascular tissue in plants that contains conductive cells, which are lignified to provide mechanical support and allow the transport of water. Considering lignin stains, cells with a high lignin content such as the tracheids in the xylem will show a deeper stain.
When identifying different tissues within a plant stem, parenchyma cells, which are generally not lignified, compose the cortex and pith of a stem. They are fundamental in plant structure and function, involved in storage, photosynthesis, and tissue repair.
Vascular tissue is recognized by the presence of both xylem and phloem cells. The xylem conducts water and minerals while the phloem is responsible for the transportation of organic nutrients.
Simple tissues, like parenchyma, consist of only one type of cell. They are fundamental in plant tissue systems and contribute to the plant's metabolic functions, along with aiding in repair and regrowth.