When you plant seeds how do they know which way is up?

Answer 1

In seed there is an embryo which mainly has two parts i)radicle ii)plumule

the radicle always grows towards gravitational force ane the plumule in direction opposite to gravity to find light

Answer 2

The growing roots and stem of a plant respond to stimulus and this determines which direction to grow in. This growth response to a stimulus is called a tropism.

When seeds germinate, the stem or shoot grows in whatever direction light originates from. For example, if light only hits a growing seedling from one side, the seedling will bend and grow towards the light. The response is known as PHOTOTROPISM. The stem of the seedling is positively phototropic because it grows TOWARDS the light.

If a seedling is grown in the dark, away from any light source, it will still grow upwards (even though it will be pale and unhealthy). This is because the plant is also sensitive to gravity, another external stimulus. In this case, the stem (or shoot) of the seedling grows AWAY from the pull of gravity, which makes it grow upward. This response is called GEOTROPISM. The stem of the seedling is negatively geotropic because it grows AWAY from the pull of gravity.

The roots of a seedling respond to the same stimulus that the stem responds to but in exactly the opposite way. They are said positively geotropic and therefore grow downwards, following the pull of gravity.

There is still a lot to be discovered in science about how exactly plants respond to different stimuli but from experiments that have been carried out, controlling factors include plant hormones. Examples of such hormones are AUXINS. Auxins cause a plant to produce more cells. The more auxins, the more cells are produced. When a seed first starts to grow, there are plenty of auxins on the shoot tip. As it continues to grow, the amount of auxins in the side of the shoot that receives the most sunlight reduces while the side that receives less sunlight produces more cells. This causes the plant to bend in the direction of the light.

I hope this has answered the question somewhat.

Answer 3

they automatically grow towards the sun when the seed cracks open and the sun is up so the plant will grow up, no worries..lol so there is not specific way to plant a seed..lol

Hope this helps

Answer 4

Geotropism. Movement towards gravity. Auxins in plant are concentrated in different regions. The root have auxins which make them grow towards the ground (gravity) and the shoot have auxins which attract them towards light (In reality, it is the opposite, the growth auxins rush away from light, so the stem away from the sunlight grows more hence the plant bends towards the light)

Answer 5

It doesn't matter which way you plant seeds, they work it out for themselves. I think you are thinking of bulbs. They are usually planted with the pointy end up.

Answer 6

They react to gravity- geotropism. Bits of starch near the root cap trigger horomones which cause the plant root to grow downward. Similarly, the shoot grows upward.

Answer 7

Um it doesn't really matter because the seed knows which way is up because it tends to grow towards the warmth of the sunlight, which is up

Answer 8

Gravity.

Answer 9

Plant seedlings automatically grow towards sunlight.

Answer 10

Gravity