Which of the following describes the structure of a dicot stem ? A) It contains a ring-shaped vascular bundle B) It contains central vascular cells C) It contains several layers of xylem that are surrounded by a ring of phloem D) It contains vascular bundles that scattered through the pith tissue

What causes temperature extremes in the desert

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Study the diagram of a cell. which structure is found only in plant cells and functions in the process of photosynthesis? w x y z