Biology

Why do plants need hormones

Hormones help to coordinate and control growth

What is phototropism

plant's directional growth response to light

What is gravitropism

directional growth of a plant in response to gravity

What is geotropism

plant's directional growth response to gravity

How do plants show positive phototropism

Auxin move to the shaded side of the shoot

the shoots bend towards the light

the plant receives more light, meaning photosynthesis can occur at a faster rate

How do plant show negative gravitropism

Auxin moves to the lower side

the shoot bend and grow away from the ground

light levels are likely to be higher further away from the ground

How do plant show positive gravitropism

Auxin moves to the lower side

the root bend and grow downwards

likely to be increased levels of water and nutrients lower down, providing stability for the plant

Name two other plant hormones

1. gibberellins

2. ethene

What does gibberellins do

stimulate seed germination

What does ethene do

involved with cell division and ripening of fruits