Pollen produced by a flower is carried by insects or blown by the wind to another flower.
This process is called pollination.
When the pollen reaches another flower, it travels to the ovary where it fertilises the egg cells to make seeds.
This process is called fertilisation.
These seeds are scattered by animals or the wind.
This process is called dispersal.
At the plant adult stage flowers start to grow.
Moving pollen from the stigma to the stamen is called pollination.
Now the flower has seeds it needs to get them out into the world.
Some flowers used wind.
Some use water.
Some protect their seeds in fruit which animals eat... and then later ....scatter.
Some seeds stick to animals.
Some are shot out by the flower.
SEED DISPERSAL
If all seeds of a plant fall under the parent plant they will grow crowded together and many will die because of lack of space or air, water, sunlight and minerals.
Therefore, it is better seeds getting scattered far and wide and have a better chance of growing in a suitable place without over crowding.
The scattering or spreading of seeds to different places is called seed dispersal.
Some seeds are sticky and have hooks.
Some seeds have wings.
Some seeds have hairy parachutes.
Some seeds are in pods.
Some seeds have small holes in them.
Some seeds have spongy layers of fibres around them.
Some seeds have smaller spongy coverings.
Examples of seed dispersal by wind A dried thistle has many seeds with hairy parachutes which can be dispersed by wind
Examples of seed dispersal by wind.
This is a dried sycamore fruit which bears many seeds with wings which can be dispersed by wind Who are the agents of seed dispersal?
Wind
Water
Animals
Examples of seed dispersal by wind;
Seeds which have wings and hairy parachutes on them are carried by the wind.
E.g. – sycamore, ash, maple, lime, dandelion and thistle
When pods dry, they split open suddenly and shooting the seeds away from the parent plant and this is easy when the wind is there.
E.g. – peas, lupins, laburnum and gorse
Some seeds have small holes in them, so they are very light in weight. When the wind rocks the plant, the seeds are scattered as if from a pepper pot.
E.g. – poppy and orchid fruits
Examples of seed dispersal by water;
Some seeds have spongy layers of fibres around them.
These can trap air so the seeds can float.
These seeds can travel, sometimes for hundreds of kilometers, from one island to another.
E.g. – Coconut
Some seeds have smaller spongy coverings which lets them float in lakes and rivers.
E.g. – water lilies, alder trees
Examples of seed dispersal by animals; Brightly coloured and juicy fruits are often eaten by animals like birds.
The hard seeds inside these fruits pass out of the animal’s body in its droppings.
E.g. – blackberries, strawberries, raspberries and gooseberries
The seeds may finish up a long way from where they were first eaten.
Animals like squirrels and jays bury some nuts, ready to eat later.
These animals often forget where they have hidden their food, and some of these seeds can grow.
Some seeds and fruits have hooks that catch on the fur or feathers of animals or on people’s clothes.
If the seeds eventually drop off on the soil, they may grow.
E.g. – goosegrass, burdock, wood avens
Examples of seed dispersal by humans;
Examples of seeds with hooks that catch on people’s clothes and shoes
Examples of seed dispersal by force. Some plants have pods that explode when ripe and shoot out the seeds. Lupins, gorse and broom scatter their seeds in this way. Pea and bean plants also keep their seeds in a pod. When the seeds are ripe and the pod has dried, the pod bursts open. and the peas and beans are scattered.