The term that describes how the stem of a plant grows toward the light is?

• A. -phototropism
• B. -geotropism
• C. +phototropism
• D. +geotropism

Answer: (C)

Plants bend toward light through phototropism. The stem shows positive phototropism, meaning growth toward the light source. The plus sign signals movement toward the stimulus; light causes more auxin to accumulate on the shaded side, making those cells elongate and the stem bend in that direction. The other terms involve gravity (geotropism) or the reverse direction (negative phototropism), which don’t describe growth toward light.