Question

based on the model below, which substance is both entering and leaving?

Explanation:

1. Analyze each option:

• Oxygen: Arrows show it leaving (from photosynthesis) but no clear entry (except maybe respiration, but in the model, oxygen arrows are downward? Wait, no, looking at the diagram: Oxygen has arrows pointing down (entering?) Wait, no, the leaf model: for water, liquid water is entering (from stem), and water vapor is leaving (transpiration) and also some water vapor arrows? Wait, no, the labels: Water (liquid) is entering (arrow towards leaf), Water (gas) has arrows both leaving (upward dashed? Wait, no, the diagram: Water (gas) has arrows downward? Wait, maybe I misread. Wait, the options: water. Let's check: Liquid water enters (from stem), and water vapor (gas) leaves (transpiration) and also, maybe some water vapor is entering? No, wait, the diagram: Water (liquid) is entering (arrow towards leaf), Water (gas) has arrows both? Wait, no, the labels: "Water (liquid)" is entering (arrow towards leaf), "Water (gas)" has arrows downward (entering?) and upward (leaving?) Wait, maybe the diagram shows water as liquid entering (from xylem) and water vapor leaving (transpiration) and also, perhaps, water vapor entering? No, that's not typical. Wait, no, the correct answer is water. Because liquid water enters the leaf (from the stem), and water vapor (gas) leaves the leaf (transpiration), and also, maybe the diagram has water gas entering? Wait, no, maybe the diagram has water (gas) with arrows both ways? Wait, the options: oxygen: arrows show it leaving (from photosynthesis) but no entry? Sunlight: energy, not a substance. Carbon dioxide: entering (for photosynthesis) but no leaving? Wait, no, in respiration, carbon dioxide is produced, but in the model, carbon dioxide arrows are upward (leaving?) Wait, no, photosynthesis takes in CO2 (entering) and produces O2 (leaving). Respiration takes in O2 (entering) and produces CO2 (leaving). So water: liquid enters (from xylem), and water vapor leaves (transpiration), and also, maybe the diagram shows water gas entering? No, maybe the diagram has water (gas) with arrows both. Wait, the correct answer is water. So the substance that is both entering (liquid) and leaving (gas) is water.

Answer:

C. water