Plant Hormones Quiz

What is the role of ethene in leaf loss?

• Increases water absorption in leaves

• Inhibits the production of auxins

• Promotes photosynthesis

• Stimulates the breakdown of cell walls in the abscission layer

Which hormone is responsible for stomatal closure during water stress?

• Ethene

• Abscisic acid (ABA)

• Auxins

• Gibberellins

What effect does abscisic acid (ABA) have on guard cells?

• Increases water potential by causing ion loss

• Promotes the opening of stomata

• Decreases water potential by causing ion gain

• Stimulates photosynthesis

What is the role of gibberellins in seed germination?

• Inhibits amylase production

• Stimulates the synthesis of amylase

• Prevents water absorption

• Maintains seed dormancy

How do auxins affect leaf loss?

• They promote leaf loss by increasing ethene sensitivity

• They inhibit leaf loss by making leaf stalks insensitive to ethene

• They increase the production of ethene

• They have no effect on leaf loss

What happens to the concentration of auxins day legnth shortens?

• It increases, promoting leaf retention

• It fluctuates randomly

• It decreases, allowing leaf loss

• It remains constant

What is the function of the aleurone layer in seeds?

• Inhibits the synthesis of gibberellins

• Protects the embryo from harsh conditions

• Synthesizes amylase in response to gibberellins

• Stores water for the embryo

What is the role of calcium ions in stomatal closure?

• They increase the water potential of guard cells

• They act as second messengers to open channel proteins

• They inhibit the movement of potassium ions

• They act as first messengers

What triggers the production of gibberellins in seeds?

• Exposure to light

• Absorption of water

• Increase in temperature

• Decrease in oxygen levels

What is the effect of abscisic acid on seed dormancy?

• It accelerates seed germination

• It has no effect on seed dormancy

• It maintains dormancy by inhibiting amylase production

• It breaks dormancy by promoting amylase production