Wednesday, May 10, 2006

HOW THE FIRST PLANTS AND ANIMALS EVOLVED AND BECAME DEPENDANT ON EACH OTHER


Plants take carbon dioxide and release oxygen in the process of photosynthesis, photosynthesis; animals inhale oxygen and exhale carbon dioxide in the process of breathing. Plants play an important role in the nature cycle. Without plants there would be no life on earth. Plants are the only organism that can make their own food. We breathe oxygen from plants. The quality of air is influenced by plants because plants can stop the movements of dust and pollutants. Through the intake of carbon dioxide plants reduce the greenhouse effect effect which comes from the burning of fossils fuels.

The first animals to evolve are called multicelled Eukaryotic animals. These evolved from colonies of single celled organisms. During this time animals were small and simple but evolved into all larger and more complex animals. The first fish evolved and the oceans were dominated by different types of invertebrates.

2, 5 million years ago, the earth and atmosphere were stable enough to support primitive life. Single celled organisms developed. The first plants to evolve were Blue-green Algae. Blue-Green Algae used sunlight and water to make food, and in the process, created oxygen. Blue-Green Algae grew in the earth seas and they began to fill the atmosphere with oxygen which made it possible for other organism to develop. Plants are the only organisms that can make their own food but animals can not makable to make their own food and they depend directly or indirectly on plants for their supply of food. All animals and the foods they eat can be traced back to plants.

Plants and animals are made by many types of cells. Plants have thick and rigid walls that consist of cellulose where as animal cells do not have these materials. Cellulose enables plants to stand upright with out an internal or external skeleton. Plants also depend on insects for distribution of the male reproductive cells. We breathe oxygen from the plants, through the process of photosynthesis. Plants absorb energy from the sun, and carbon dioxide from the air and water from the soil. Animals take part in this cycle through respiration. Respiration is the process where oxygen is used by organisms to release energy.

Plants make the Earth’s atmosphere livable for humans and animals by changing carbon dioxide into oxygen. Plants are used by both humans and animals because we can use plants as food, plants as medicine, or plants as decoration. Leaves are the main food makers for plants. Because they capture energy from sunlight, and turn water and carbon dioxide into sugar and starch. One can undertake research science on plants, how plants grow, why they change colour, and one can also learn about different plants and ecosystems around the world, and how they are affected by human habitats. .

Plants play an important role with regard goods; they provide fibres and these in turns provide clothing. Wood is also used to build our houses, and burnt to keep us warm and cook our food. Plants importantimportant Plants important play important an important part in the quality of water because they hold the soil in place and control stream flow and filter sediments from water. Plants also prevent erosion.
They also play an important role by role byrole by providing the necessary habitat for wildlife and fish populations. The amount of sunlight and rainfall are limiting factors for both plants and animals because both affect plant growth.

References

Wikipedia contributors. Segmentation [internet].Wikipidia,the free encyclopedia;2006 march 24,11:10 UTC [cited 2006 May 08] available

Linette Netshiheni
CSIR
Pretoria
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Cell: 0820446442
Tell: 012 841 2133
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tnetshiheni@csir.co.za
Weblog: http://tnesthiheni.blogspot.com/

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