Plant Growth and Development Question 19

19. What causes a green plant exposed to the light on only one side, to bend toward the source of light as it grows ?

[2015 RS]

(a) Green plants seek light because they are phototropic

(b) Light stimulates plant cells on the lighted side to grow faster

(c) Auxin accumulates on the shaded side, stimulating greater cell elongation there.

(d) Green plants need light to perform photosynthesis

Show Answer

Answer : c

Hints & Solutions

(c) Auxin stimulates cell elongation. It accumulates on shaded side which results in more elongation of cells towards shaded side of the plant. This causes bending of the plant towards source of light.