Aim: How do ranges of tolerance affect the distribution of organisms?

1. Aim: How do ranges of tolerance affect the distribution of organisms? Do now:Write an example of a limiting factor and explain how affects the organism Vocabulary: limiting factor,distribution,tolerance,estuaries

2. Limiting factor • If an organism is to live and survive in its habitat, it must be able to obtain the materials it needs for growth and reproduction. Anything that is essential to an organism and for which there is competition is called a limiting factor. In an open field, the oxygen content of the air would not be a limiting factor for a number of grazing animals. But if the same number of animals were to be confined inside a closed barn for some time, then oxygen becomes a limiting factor.

3. Example of limiting factor • Let us take cattails for example. These plants grow along the shore of a lake where the water is not too deep and soil condition is soft and muddy. Beyond that particular area, the water will be deeper. In that depth of water, this cattail won't live nor grow. So you could really say that the depth of the water as well as the soil condition becomes the limiting factors of the growth of cattail. They compete within that area and cannot go beyond.

4. Tolerance • The continuous survival of any organism depends upon certain specific sets of conditions in the surroundings. If such conditions are limited, then the organism's survival is likewise inadequate. However if the organism learn to survive, then they are able to tolerate any set of conditions surrounding them. Tolerance is the ability of organisms to withstand variety of environmental conditions.

5. Example of Tolerance • A typical example of organisms having a tolerance would be estuaries. This is a biome or ecological region where river and stream water merges with the salty sea. Many organisms like worms, clams, oysters and fishes live in this area. They survive because of their ability to tolerate an area with a high salt concentration.

6. Conclusion • All living things are limited by factors in the environment. • Any abiotic or biotic factor that restricts the numbers ,reproduction, or distribution of organisms is called a limiting factor. • The ability of any organism to survive when subject to abiotic or biotic factor is called tolerance.