Question

What is plants response to gravity called ?

Answer 1

Geotropism

Explanation:

It is the coordination and responses for a plant's growth towards gravity. There are two types of geotropism, positive geotropism and negative geotropism.

Here is a picture to see the differences between the two:

Seedlings tend to be negatively geotropic, so the plant will grow up, while the roots are positively geotropic, and therefore grow down.

All of these responses are primarily controlled by a plant hormone called auxin. Auxins control the rate of growth and elongation of a part of a plant.

You can read about how they work here:

http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway/understanding_organisms/control_plant_growthrev3.shtml