Question

7. A student observed that the roots of a potted plant grew toward the bottom of the pot even when it was placed sideways. What conclusion can be drawn about this response?
A. The plant roots show negative phototropism.
B. The plant roots are unaffected by gravity.
C. The plant roots demonstrate positive geotropism.
D. The plant roots show thigmotropism.
8. Which situation best explains adaptation rather than an immediate response to stimuli?
A. A cactus closing its stomata during daytime to prevent water loss.
B. A vine wrapping around a nearby stick for support.
C. A Venus flytrap snapping shut when touched by an insect.
D. A sunflower turning toward sunligh/broughout the day.

Answer 1

7. C. The roots demonstrate positive geotropism — they grow toward the direction of gravity (downward), even when the pot is turned.

8. A. A cactus closing its stomata during daytime is an adaptation (evolved water‑conservation strategy, e.g., CAM photosynthesis), whereas the other choices are immediate responses (tropisms or rapid movements).