Saturday, January 5, 2008

Do seeds die when birds eat them?
When birds eat many small fruits, they also eat the seeds inside them. They digest the fruit, but the seeds usually survive and come out in the bird's droppings. The seeds can germinate and grow, with the droppings providing the fertiliser they need for a good start in life.

How do plants grow from cuttings?
When a storm breaks branches from willow trees growing by a river, these fall in the water, float downstream, and can get stuck in the bank. The broken-off branches may make roots in the mud and grow into new trees. Many plants can grow in this way, and gardeners use the process to 'take cutting' from plants.

The race to reproduce
On a forest floor in early summer, plants are busily reproducing - in a variety of ways. Wild strawberries develop flowers and grow 'mini-plant' on long stalks called runners. Ferns and mosses make spores on the undersides of their leaves, or in special containers called capsules. They are not as colourful as flowers, but they are still easy to see.

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Wednesday, December 26, 2007

Seeds on the move
Seeds need to move away from the plant they came from, so that they can grow in a clear space with plenty of light. Some seeds travel on the wind, dandelion seeds, for instance, use 'parachutes' to travel, while sycamore seeds use 'propellers'. Other seeds have tiny hooks which attach to the fur of a passing animal (or to our trousers and sweaters) and get carried about in that way. Coconut seeds are covered with thick fibres, so that the seed floats, and they are carried by the sea from island to another. The liquid inside a coconut gives the young plant some fresh water, which it needs when it lands on a sandy beach and starts to grow.

Seeds young and old
Arctic lupin seeds trapped in the frozen ground have germinated almost 10 000 years after being shed. Living seeds have also been found in the tombs of ancient Egyptians. But willow seeds last only a few months.

Tag :seeds

Friday, December 14, 2007

PLANTS REPRODUCE

Plants have to reproduced, just as animals do. First of all, most develop flowers which are then fertilised or pollinated, to produce seeds. The seeds ripen, and are scattered far and wide, eventually growing into new plants. Ferns and mosses reproduce in a different way. They do not have flowers. Instead of making seeds, they make microscopic spores which drift through the air.

How are flowers pollinated?
Flowers contain male parts which produce a fine dust called pollen, and female parts which produce seeds when they receive pollen from another flower. Some plants rely on the wind to spread their pollen, but most use animals. Insects, birds and bats visit flowers to feed on their sugary nectar. As they travel from bloom to bloom, they carry pollen with them, pollinating or fertilising the flowers they visit.

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:flower pollinated

Wednesday, December 5, 2007

All life depends on plants
Almost every living thing depends on plants for its food supply. Even the leopard and lion, which only eat meat, are actually feeding on plants, because that is what feeds their prey. In the same way, if you drink milk you are really consuming grass, there wold be no cows to give us milk. The grass turns the Sun's energy into food, the cow turns that energy into milk, and you use that energy to kick a football around, or dance or do homework. Even reading uses up some of that energy. The link from grass to cows to humans, or from grass to antelope to lions, is called a food chain.

From seeds to 'sweetcorn'
Germination : The seed absorbs moisture from the soil and starts to grow.
Lightwards : The shoot grows up, while the roots grow down.
Growth : More roots grow below ground, and more leaves above ground.
Flowering : Finally, the maize plant flowers and then sets seed, producing a new cob of corn.

Tag :plants began

Thursday, November 29, 2007

How do plants drink?
Although plants can absorb a little water through their leaves, they get most of the water they need by drawing it up from the ground through their roots. The roots are in close contact with the particles of soil around them. Tiny rootlets connected to the roots extend into the soil, and these draw in moisture. If you pull up a plant, you can see the delicate white roots, but you cannot see the microscopic rootlets that absorb water. If a plant is pulled up, the rootlets are broken. As soon as they stop working, the plant starts to wilt.

Insect-eating plants
Some plants that grow in poor soil get the nutrients they need by trapping and digesting passing insect. Most produce and attractive scent or glistering drop that look like nectar to lure insect to their doom. Sticky glue or a pool of liquid keeps an insect in the trap while the plant closes and begins to digest it.

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Tag :eating plants