Select the correct answer.

Question

Tropical forests contain dense trees, which allow less sunlight to penetrate. Emergent trees are trees that grow to a height of more than 45 to 55 meters, above the usual height of trees in tropical forests. Which system provides the best possible explanation for why these trees grow to those heights?
A.
shunted growth pattern
B.
homeostasis
C.
due to less exposure to sunlight
D.
phototropism

Answer 1

The correct answer is: D. phototropism.

Phototropism is the growth of plants in response to light, and trees in tropical forests often grow taller to reach sunlight that penetrates the canopy. Emergent trees, in particular, grow above the dense canopy to access the sunlight needed for photosynthesis.