A plant is growing in middle of the patch of bare dirt; there’re no other plants in twenty meters except for one other plant 2 meters away. This second plant has the straight stem and is one meter tall. The first plant sends out the shoot along the ground directly towards the one-meter-tall plant. When shoot reaches that plant’s stem it grows up stem by winding around it and around.
1. How did the shoot ‘know’ to grow straight to other plant? prepare down a hypothesis first.
2. How, when the shoot tip touched other plant’s stem, did the shoot switch from the growing straight to growing in spiral? prepare down a hypothesis first.