Plant hormones

What hormone causes fruit ripening?

Ethene

What artificial hormone ripens plants

Ethylene

What is the term for plants that can ripen with ethylene after being picked?

Climacteric plants

What hormone controls seed germination

Gibberellins

What is the term for long, thin stems due to lack of light?

Etiolation

What is the term for re-absorbance of nutrients into the leaf?

Senescence

What is the term for leaves falling off?

Abscission

Why does senescence occur?

Re-absorb nutrients in leaves before they fall off (frost damage).

Steps to leaves falling off

Cytokinin level drops → senescence → reduction in auxin production → cells sensitive to ethene → cell walls dissolve → abscission occurs

What does Abscisic acid do?

Stomatal closure during drought

What is the organ at the top of the plant where new growth occurs called?

Shoot Apical Meristem

What is the name for where side shoots begin?

Lateral meristem tissue

What hormone triggers stem elongation?

Gibberellins

Which hormone triggers tropisms and apical dominance?

Auxins

What is apical dominance?

Where the main shoot of a plant (top bit) grows taller and releases auxins, which inhibit lateral growth.

How does auxins cause cell elongation (simple)

Allows cell wall to stretch