The microscopic world that feeds the whales
Blue whales feed on very small animals called krill, using their huge sieve-like mouth to catch thousands at a time. The krill feed on microscopic animals and plants called plankton that float in the upper layers of the ocean. So blue whales, which are the largest living creatures in the world, are directly dependent on some of the smallest creatures for their food.
After this, find out about kinds of microscopic
Saturday, November 24, 2007
Friday, November 23, 2007
What is the smallest living thing?
The smallest living things are viruses. They are like car engines without any wheels or bodywork attached, they have no way of moving around and no cell wall, unlike other living thing. Viruses do not even have any way of reproducing themselves. In order to produce more viruses, they have to invade other cells and take them over. This is why viruses cause diseases. When you catch a cold, the cells in your nose have been taken over by viruses so that they can reproduced themselves.
How to live on leaves
Animal such as deer and horses have bacteria in their digestive systems that allow them to digest grass and leaves. Our ancestors once had these bacteria too, and attached to your intestine is an 'appendix'. This empty pocket is all that remains of the large structure which aonce held leaf-digesting bacteria.
The smallest living things are viruses. They are like car engines without any wheels or bodywork attached, they have no way of moving around and no cell wall, unlike other living thing. Viruses do not even have any way of reproducing themselves. In order to produce more viruses, they have to invade other cells and take them over. This is why viruses cause diseases. When you catch a cold, the cells in your nose have been taken over by viruses so that they can reproduced themselves.
How to live on leaves
Animal such as deer and horses have bacteria in their digestive systems that allow them to digest grass and leaves. Our ancestors once had these bacteria too, and attached to your intestine is an 'appendix'. This empty pocket is all that remains of the large structure which aonce held leaf-digesting bacteria.
What tiny creatures share your home?
If you think your house just belongs to you and your family, think again. As well as flies, spiders and woodlice, there are many microscopic animals and plants living with you. No matter how clean your house is, the carpets, armchairs and mattresses are probably full of tiny animals called house dust mits. These feed on the flakes of skin that you shed every day. Before the mite get to them, these bits of skin provide food for microscopic moulds, and the mites eat the moulds along with the skin. As long as you are not allergic to moulds or dust mites, neither will do you any harm.
Unseen in the pond
A drop of pond water can be full of the most astonishing animals and plants, visible only with a microscope.
If you think your house just belongs to you and your family, think again. As well as flies, spiders and woodlice, there are many microscopic animals and plants living with you. No matter how clean your house is, the carpets, armchairs and mattresses are probably full of tiny animals called house dust mits. These feed on the flakes of skin that you shed every day. Before the mite get to them, these bits of skin provide food for microscopic moulds, and the mites eat the moulds along with the skin. As long as you are not allergic to moulds or dust mites, neither will do you any harm.
Unseen in the pond
A drop of pond water can be full of the most astonishing animals and plants, visible only with a microscope.
Thursday, November 22, 2007
THE LIFE OF MICROSCOPIC
A huge part of the living world is too small to be seen except under a microscope, which magnifies everything tens or even thousands of time. Some of these microscopic creatures are harmful to us, causing diseases or making food rot. Others are useful, such as the yeast that help us make bread, and the bacteria that make yogurt and cheese.
What's living on you?
In the wild, most animals have fleas, lice and other small parasites living on their bodies. The same was true of our ancestors. A large, warm-blooded creature such as a human being is like a walking restaurant to smaller forms of life, and the meals are all free. Today we use soap and water to get rid of these small parasites from our bodies and our clothes, and if all else fails we use chemicals to kill them. But there are many microscopic creature sharing our lives that we do not even know about. Most of them do us no harm at all. Some are even beneficial, such as a bacteria which live on our skins and in our intestines.
What's living on you?
In the wild, most animals have fleas, lice and other small parasites living on their bodies. The same was true of our ancestors. A large, warm-blooded creature such as a human being is like a walking restaurant to smaller forms of life, and the meals are all free. Today we use soap and water to get rid of these small parasites from our bodies and our clothes, and if all else fails we use chemicals to kill them. But there are many microscopic creature sharing our lives that we do not even know about. Most of them do us no harm at all. Some are even beneficial, such as a bacteria which live on our skins and in our intestines.
What is coal?
Coal is just old wood, twigs and leaves. It began as forests, which grew in swampy land more than 300 million years ago. When the trees died they fell into the swamp water, which prevented them from breaking down properly. They turned into peat, a soft brown substance. The huge pressure of rock layers building up above turned the peat into coal.
Prehistoric plants
Animals are not the only things that can turn into fossils. Coal sometimes contains the fossilised bark and leaves of giant ferns and clubmosses, trees that grew in swampy forests more than 300 million years ago.
Tracks through time
Animal footprints can be preserved in the rocks, and so can insect trails or even the traces left on the seabed by worms and jellyfish. However, these small, delicate structures can only be preserved in rock that originally comes from mud or sand.
Coal is just old wood, twigs and leaves. It began as forests, which grew in swampy land more than 300 million years ago. When the trees died they fell into the swamp water, which prevented them from breaking down properly. They turned into peat, a soft brown substance. The huge pressure of rock layers building up above turned the peat into coal.
Prehistoric plants
Animals are not the only things that can turn into fossils. Coal sometimes contains the fossilised bark and leaves of giant ferns and clubmosses, trees that grew in swampy forests more than 300 million years ago.
Tracks through time
Animal footprints can be preserved in the rocks, and so can insect trails or even the traces left on the seabed by worms and jellyfish. However, these small, delicate structures can only be preserved in rock that originally comes from mud or sand.
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