Plant Hormones

Question 1

Auxin (IAA)

Answer 1

Promotes plant growth via elongation of developing cells

Question 2

Phototropism

Answer 2

Plants response to light

Auxin is produced in the tips of shoots and roots

If there is a barrier between plant and sun, plant will release auxin on the more shaded side, allowing it to grow around the barrier

Question 3

Gibberellins

Answer 3

Promote cell growth

Involved in promotion of fruit development and seed germination

High concentrations can cause bolting

Question 4

Bolting

Answer 4

Rapid increase of length by stems, such as when rice was bolted in response to fungi containing the hormone

Question 5

Cytokinins

Answer 5

Stimulates cell division

Influence organ development (determines if roots/shoots will develop)

Delay aging of leaves

Often added to prolong plant’s usefullness

Question 6

Ethylene

Answer 6

Gas that promotes fruit ripening

Involved in stimulating flower producion

Influences leaf abscission (aging and dropping of leaves)

Question 7

Abscisic Acid (ABA

Answer 7

Growth inhibitor

Maintains dormancy in seeds