Chapter 38

Question 1

Phototropism

Answer 1

Movement or growth in a plant in response to unidirectional light

Question 2

Gravitropism

Answer 2

Movement or growth of a plant in response to gravity

Question 3

Thigmotropism

Answer 3

Movement or growth in a plant in response to contact with an object

Question 4

Thigmonasty

Answer 4

Plant growth or movement in response to being touch

- folding leaves

Question 5

Nastic movement

Answer 5

Reversible or temporary movements in response to a stimulus (regardless of stimulus direction)

Question 6

Circadian rhythm

Answer 6

A 24-hour cycle of response in plants

Question 7

Phytochrome

Answer 7

A blue-green pigment that exists in two forms and signals the light switch in de-etiolation

Question 8

Vernalization

Answer 8

Refers to a low-temperature stimulation flowering (stratification in seeds is similar)

• requires exposure to sufficient periods of cold temperatures

Question 9

Statoliths

Answer 9

Amyloplasts that move in the plant root and shoot tip to help in responding to gravity

Question 10

Triple response

Answer 10

The slowed elongation, thickening and turning of an underground shoot in response to an obstacle