1. Plants are rooted to the spot so they are not mobile
2. Plants do not have a rapidly responding nervous system

1. Water enters the seed
2. The embryo in the seed is activated and begins to produce gibberellins
3. Gibberellins stimulate the production of enzymes like amylases and maltases
4. These enzymes hydrolyse the food stores in the seed endosperm
5. The embryo now has sugars to produce ATP for growth

There is evidence that the level of the plant hormone abscisic acid (ABA) also helps to determine when germination occurs.

Seeds that cannot produce gibberellins do not germinate, but if gibberellins are applied to the seeds externally they germinate normally.

Seeds can be bred without the gene that produces gibberellins, or inhibitors can be applied to prevent their production.

Gibberellins cause elongation of plant stems during growth by increasing the length of the internodes, which are the regions between the leaves on a stem.

Plants that are unable to synthesise many gibberellins have shorter stems.

This makes the plants less vulnerable to damage by weather and harvesting.

Plants respond to their environment by producing hormones that are transported throughout the plant and have an effect in different parts of the plant.

Gibberellins are plant growth regulators that stimulate seed germination and regulate plant height via stem growth.