Module 10B: Plant Tropism

Question 1

Plants, although stationary, have
the remarkable ability to sense
and respond to their environment.
This responsiveness is crucial for
their survival.

Answer 1

Plant Sensitivity

Question 2

Types of Stimuli

Answer 2

● Light
● Gravity
● Touch

Question 3

● Growth towards light
● Essential for maximizing photosynthesis

Answer 3

Phototropism

Question 4

● Growth in response to
gravity
● Roots grow downwards, stems
grow upwards

Answer 4

Gravitropism

Question 5

● Response to touch
● Common in climbing plants like vines

Answer 5

Thigmotropism

Question 6

● Promote cell elongation
● Concentrate on the shaded side of a
plant, causing it to bend towards
light

Answer 6

auxin

Question 7

● Promote cell division
● Work with auxins to control growth
and development

Answer 7

cytokinins

Question 8

● Stimulate stem elongation
● Play a role in breaking seed
dormancy

Answer 8

Gibberellins

Question 9

● Influences fruit ripening
● Affects leaf abscission and flower
wilting

Answer 9

Ethylene

Question 10

sunflower movement is due to what hormone

Answer 10

auxin

Question 11

seed germination is attributed to what hormone

Answer 11

gibberellins

Question 12

leaf frop is because of what hormone

Answer 12

ethylene

Question 13

● Internal Biological Clocks
● Operate on a roughly 24-hour cycle
● Regulate various physiological processes

Answer 13

Circadian Rhythms

Question 14

How Circadian Rhythms Affect Plant Behavior

Answer 14

flower opening, leaf movement