A plant pot is placed on its side. Which diagram shows a plant with roots showing gravitropism and shoots showing phototropism?
▶️ Answer/Explanation
Ans: C
Gravitropism causes roots to grow downward (toward gravity), while phototropism makes shoots grow upward (toward light). In diagram C, the roots curve downward, and the shoots bend upward, correctly showing both responses.
Other diagrams show incorrect combinations: some have roots growing upward (A, B) or shoots not responding to light (D). Thus, C is the correct representation of these tropic responses.
The diagram shows a plant shoot growing towards the light.
What is the name of this plant shoot’s response to light?
A) gravitropism
B) photosynthesis
C) phototropism
D) reflex
▶️ Answer/Explanation
Ans: C
Phototropism (C) is the growth response of plants toward light, controlled by auxin hormones. Gravitropism (A) responds to gravity, photosynthesis (B) is an energy process, and reflexes (D) are rapid animal responses. The light-directed growth is classic phototropism.