All posts by jshulkin

Tropism

Tropism

Tropism is defined as the turning of all or part of an organism in a particular direction in response to an external stimulus. Basically, the environment influences an organisms behavior. Tropism in response to sunlight is known as heliotropism. Sunflowers are thought to follow the sun’s path throughout the day; however, this misconception is because of the uniform alignment due to heliotropism in the bud stage. The buds of sunflowers are heliotropic and face east when flower heads appear. Sunflowers can even be used as living compasses, since they are always facing east.