The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm), yet short, vein that receives venous return from the upper half of the body, above the diaphragm.
B. Is correct because in mutualism both species benefit. It could be symbiosis but mutualism is more specific.
Answer:
When the soil of a plant runs too low of available water, the water chains in the xylem become thinner and thinner due to less water. Effectively, the plant is losing water faster than it is absorbing it. When this happens, the plant loses its turgidity and begins to wilt.
Cell, tissue, organ, organ system, organism...................................................................
