An eccentric millionaire botanist has offered a $25,000 scholarship to anyone who can successfully get a plant to grow through a vertical maze in complete darkness. The maze is not in a box; the maze is simply drawn on the wall, and the contestants must get their plant to grow in a pattern that matches the path through the maze. You need the money and feel confident that you can accomplish this task. Which of the following techniques will help you succeed

Option B, Apply auxin directly to the lower part of the stem opposite from the direction you want the stem to bend.

Explanation:

Options for the question are

A) Apply auxin directly to the shoot tip on the side to which you want the tip to bend.

B) Apply auxin directly to the lower part of the stem opposite from the direction you want the stem to bend.

C) Inject compounds that block auxin receptors into the part of the stem opposite from the direction you want the stem to bend.

D) Plant the roots in two different pots, and apply auxin to the root bucket that is on the same side as the direction you want the plant to bend.

Solution

Auxin is responsible for stem elongation by inhibiting growth of lateral buds. The movement of auxin is opposite to the direction of elongation of cells. Generally, Auxin moves to the dark side which is opposite to the direction i.e the lighter side in which cell elongate . Due to this growth pattern, the stem tip gets curved towards the light.  

Hence, option B is correct