Use the Following Information When Answering the Corresponding Question(s)

Use the following information when answering the corresponding question(s).
The shade avoidance response is a plant's way of changing its growth pattern when it is being shaded by another plant.Upon exposure to shade,many plants will grow taller,flatten their leaf angle,and extend their leaves further from their stems in order to reach full sunlight.Research performed by Pierik et al.(Interactions between ethylene and gibberellins in phytochrome-mediated shade avoidance responses in tobacco.2004.Plant Physiology 136:2928-36;online at http://www.plantphysiol.org/cgi/content/full/136/2/2928)examined the role of ethylene and gibberellins on the shade avoidance response in tobacco plants.The shade avoidance response is known to involve phytochromes.
-Refer to the paragraph on the research done by Pierik et al.Ethylene's role in the shade avoidance response in tobacco plants is related to its role in fruit ripening,leaf abscission,and senescence.