Biology, Eighth Edition (Raven)

Chapter 41: Sensory Systems in Plants

Learning Outcomes

• Understand the chemical basis of the phototropic and photomorphogenic responses and how they are altered by light of various wavelengths.
• Differentiate between thigmotropism and thigmonasty.
• Describe the physical versus physiological basis of gravitropism.
• Understand the numerous kinds of movement exhibited by otherwise immobile plants.
• List the seven major types of plant hormones, their basic effects on plant tissues, and several of their commercial applications. Which one is a gas? Which one induces formation of winter buds?
• Describe the chemical nature of the only naturally occurring plant auxin.
• Compare plant hormones with animal hormones.
• Describe dormancy and the factors that release it.