Final answer:
Dicots have two cotyledons with net-like venation in leaves and a vascular ring in the stem, while monocots have one cotyledon with parallel venation in leaves and scattered vascular bundles. Adaptations to cold in leaves include modifications like a thicker waxy coating.
Step-by-step explanation:
The differences in the structures of dicotyledonous plants (eudicots) and monocotyledonous plants (monocots) are quite distinct. Eudicots are characterized by having two cotyledons in their seeds, whereas monocots only have one cotyledon. A notable difference in leaf structure is that eudicots have leaves with a reticulate, net-like venation pattern, whereas monocots have leaves with parallel venation. Furthermore, in eudicots, the vascular tissue in the stem typically forms a ring, while in monocots, the vascular bundles are scattered throughout the stem.
Besides leaf structure, eudicots often have flower parts that come in multiples of four or five, and they have a main root that develops from the embryonic radicle, which usually anchors the root system. Monocots, on the other hand, usually have flower parts in multiples of three and lack a main, central root, instead having a fibrous root system where all roots are of similar size.
Regarding the adaptations to cold temperatures, some plants have developed leaves with special features such as smaller leaf surface areas, thicker waxy coatings, and other modifications to reduce water loss and protect from freezing temperatures.