Plant Responses Flashcards
Gravitropism / Geotropism
a directional growth response to gravity
Tropism
A directional growth response either positive (towards) or negative (away) from a stimulus
Phototropism
A directional growth response to light
Apical dominance
The inhibitory influence of a shoot tip or apical bud on lateral growth
Abiotic stress
Non living (eg lack of water) factors that have harmful effects on plants
Cytokinin
Plant hormone responsible for growth in developing fruit
Ethylene (ethene)
Plant hormone responsible for inducing fruit ripening
Gibberellins
Class of plant hormones involved in stem elongation & seed germination (breaking dormancy)
Auxin
Plant hormone responsible for apical dominance, phototropism & cell elongation
Chemotropism
Directional growth down chemical gradient
Eg pollen tubes grow towards overy where fertilisation occurs
Thigmotropism
Growth around/on an object to gain support, eg. Ivy winding around
Nastic response
Non-directional response to external stimulu
