DBQ p.118- Comparing Stem Structure
1) Because the diagram shows a tissue, thus, the areas on the diagram represent areas of tissue.
2) Both dicotyledon stems and monocotyledon stems have epidermises. They both have cortexes too.
3) In both dicotyledon stems and monocotyledon stems, the phloem is closer to the epidermis than the xylem is. In both types of stems the xylem is closer to the center of the stem than the phloem is. The dicotyledon stem has woody fibers attached to some phloems, which makes the phloems be farther away from the epidermis, whereas the monocotyledon stem does not have woody fibers attached to any phloems, which makes the phloems be closer to the epidermis. While the dicotyledon stem contains vascular bundles of irregular shapes, making them face in different directions (but phloems still face the outside while the xylems face the inside), the monocotyledon stem contains only near-identically oval vascular bundles, making them face in roughly the same directions.
4) Monocotyledon stems cannot thicken in the same way as dicotyledon stems because they do not have a cambium between the phloem and xylem, which the dicotyledon stem uses as its lateral meristem to thicken. This is an indication that monocotyledon stems are incapable of producing extra xylem tissue to thicken.
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