SSC
BIOLOGY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
more auxin diffuses to the shaded side to increase cell elongation
|
|
|
more auxin diffuses to the unshaded side to increase cell elongation
|
|
|
more auxin diffuses to the shaded side to decrease cell elongation
|
|
|
more auxin diffuses to the unshaded side to decrease cell elongation
|
Detailed explanation-1: -The correct answer is Auxin accumulates towards darker side to induce greater cell elongation.
Detailed explanation-2: -Unidirectional light is thought to induce lateral auxin flow to the shaded side and promotes the growth on that side (Friml et al., 2002b), which seems to be driven by PIN1, PIN3, and ABCB19.
Detailed explanation-3: -More auxin is transported down the shady side, and less auxin is transported down the illuminated side. Auxin promotes cell elongation, causing the plant to grow more on the shady side and bend in the direction of the light source.
Detailed explanation-4: -When light falls on the plant, auxin moves to the darker side of the plant(Shaded region). It causes the cells in that region(darker side) to grow larger than the cells corresponding to the lighter side of the plant. This causes the plant to bend towards the source of light.