Coordination in plants

Stimulus

change in an organisms surroundings

Receptor

cell or organ that detects a stimulus (e.g. eye detects light)

Effector

organ that brings about a responds (e.g. muscle in arm contracting to move hand away from a hot object)

Tropism

a growth response to a stimulus in plants

Phototropism

growth response to the direction of the light. if growth is towards light it is positive phototropism as seen in shoots so that they can receive light for photosynthesis

Geotropism

growth response to gravity. Shoots show negative geotropism

what is the response for light in shoots

phototropism - grows towards light source (positive phototropism)

what is the response to gravity in shoots

geotropism - grow away from direction of gravity (negative geotropism)

light response in roots

most species show no response , some grow away from light (negative phototropism)

gravity response in roots

geotropism - grow towards direction of gravity (positive geotropism)

root response to water

hydrotropism - some species may grow towards water (positive hydrotropism)