Test Your Knowledge on Plant Hormones

Study Notes

Effects of Plant Hormones:

Survival of plants depends on their ability to respond to changes in their environment
Plants respond to several types of stimuli including light, gravity, physical objects, herbivory, water, and physical touch
Plants do not possess a nervous system; their responses rely on chemical substances that are released or altered in response to a stimulus
Phytochromes are plant pigments that react to different types of light, leading to different plant responses
Phytochrome pigments exist in two forms: PR (inactive) and PFR (active)
Absorption of different wavelengths of light causes a reversible conversion between the PR and PFR forms of phytochrome
Phytochrome is responsible for seed germination: red light triggers germination while far-red light prevents it
Phytochrome controls flowering: long day plants flower when the nights are short, high levels of PFR activate flowering, and PFR activates expression of genes that stimulate flowering
Phytochromes are also involved in plant responses to light and gravity by acting as transcription factors
PFR can move into the nucleus via the nuclear pores and bind to a protein known as phytochrome-interacting factor 3 (PIF3)
PIF3 can initiate transcription and activate various different genes, controlling many different aspects of plant growth and development
The length of night can be detected by a plant because it determines the quantities of different forms of phytochrome in the leaf

Description

Do you know how plants respond to changes in their environment and stimuli? Test your knowledge with our quiz on the effects of plant hormones. Learn about the role of phytochromes in seed germination, flowering, and plant responses to light and gravity. Discover how different wavelengths of light can trigger reversible conversions in phytochrome pigments and how PFR can activate genes that control plant growth and development. Take the quiz and become an expert on plant hormones!