Plant Responses and Adaptations

Light, heat, and other things that produce a response are examples of a(n) ________________.

A plant's movement toward or away from a stimulus is called _________________.

Plant roots grow downward in response to ______________.

The response of a place to changes in light is called _______________.

The roots of a willow tree show ______________ as they grow toward a water source.

In Darwin's experiment, the plant shoots with _______ turned toward light, while the plants without tips did not.

Scientist Frits Went believed that a(n) ______________ allowed the plant shoots to bend toward light.

Chemicals that stimulate plant growth are called _______________.

The plant shoots bend toward light because auxins cause cell growth on the __________ of the stem, making it longer.

Adaptations help plants survive in many kinds of __________________.