Controlling Plant Growth (B1)

If a plant is grown with hardly any light the plant is usually yellow in colour and the stem is always facing the way it can get most light. Usually the stems are quite long and straggly

Tropisms:

Stimuli plants are sensitive to: Light, Water and Temperature

Their responses are called tropisms

Positive tropisms - plant grows TOWARDS stimuli

Negative tropisms - plant grows AWAY from stimuli

Phototropisms:

Growth in response tothe direction of light

Plants SHOOTS grow POSITIVELY TOWARDS the light

Plants ROOTS grow NEGATIVELY AWAY from the light

Auxin:

Auxin is a plant hormone. It allows shoots to grow towards the light. Auxin is released in the tip of the shoot. The auxin travels the…