Plant hormones (coordination and control) Flashcards
What is a stimuli?
a change in the surrounding environment e.g. temperature, light intensity
What is diffusion?
the movement of molecules or particles down a concentration gradient (high –> low concentration)
What is tropism?
the ability of plants to detect a stimulus and respond to it (either by growing towards or away from it)
What is geotropism?
growing towards/ away from gravity
What is phototropism?
positive - growing towards light
negative - away from light
What is hydrotropism?
When the roots grow towards a water source
What are auxins?
a plant hormone responsible for aiding plant growth
How does the growth of shoots respond to light?
in the shoots, the auxins diffuse away from the light and stimulate cell elongation, causing the shoot to grow in the direction of the light
How does growth in the roots respond to gravity?
in the roots, auxins diffuse downwards (towards gravity) and inhibit cell elongation, causing the roots to tip and grow downwards
What is cell elongation?
When cells get longer - water moves into the cell and stretches it out
