There always has to be a dominant allele
What hormone helps plants move toward a stimulus?
A.)Ethylene
<u>B.)Auxins</u>
C.)Acids
Auxin moves to the darker side of the plant, causing the cells there to grow larger than corresponding cells on the lighter side of the plant. This produces a curving of the plant stem tip toward the light, a plant movement known as phototropism. Auxin also plays a role in maintaining apical dominance

Hope It Helps you!
The first three answers are natural changes, while the last three are because of human intervention.