1) carbon dioxide makes up less than 1 precent pf earths atmosphere, and oxygen makes up about 20 precent. These precentages are maintained most directly by a) respiration  and photosynthesis b) the ozone sheild c) synthesis and digestion d) energy recycling in ecosystems 2) The exchange of respiratory gasses and the synthesis of organic compounds by autotrophs are processes that are directly involved in the a) maintenance of soil fertility in an ecosystem b) transfer of materials in the carbon-hydrogen-oxygen cycle c) transfer of nitrogen through a food chain d) distribution of minerals in an ecosystem  3) in an ecosystem, which component is not recycled a) water b) oxygen c) energy d) carbon 4) millions of acers of tropical rain forest are beung destroyed each year. which change would most likely occur over time if the burning and clearing of these forests were stopped a) an increase in the amount of atmospheric pollution produced b) a decrease in the source of new medicines c) an increase in the amount of oxygen released into the atmosphere d) a decrease on the number of species 5) respiration and photosynthesis have the least effect on the cycling of a) carbon b) nitrogen c) oxygen d) hydrogen 6) a five year study was carried out on a population of algae in a lake the study found that the algae in a lake population was steadily decreasing in size. over the size. Over the five-period this decrease most likely led to a) a decrease in the amount of nitrogen released into the atmosphere b) an increase in the amount of oxygen in the lake c) an increase in the amount of water vapor present in the atmosphere d) a decrease in the amount of oxygen released into the lake 7) which processes are most directly involved in the cycling of carbon, hydrogen, amd oxygen between plants and animals in an ecosystem  a) transpiration and excretion  b) photosynthesis and respiration  c) dehydration and hydrolosis d) decomposition and succession 8) as water cycles through an ecosystem, which process returns in to the atmosphere  a) hydrolysis  b) transpiration c) condensation d) cyclosis 9) which processes are involved in the water cycle a) respiration and photosynthesis only b) transpiration and excretion only c) respiration, photosynthesis, evaporation and condensation only d) respiration, photosynthesis, transpiration, excretion, evaporation, and condensation 10) which two water life functions of animals help maintain the water cycle by recycling water back into the environment a) digestion and regulation b) synthesis and locomotion c) respiration and excretion d) reproduction and growth 11) decomposition and decay of organic matter accomplished by the action of a) green plants b) bacteria and fungi c) viruses and algae d) scavengers 12) nodules on the roots of legumes contain a) nitrogen-fixing bacteria which help produce nitrates b) denitrifying bacteria, which produce amino acids c) bacteria that release uric acid into the soil d) bacteria that produce protein for absorption by plants 13) shawangunk grasslands national wild life refuge has been developed from an abandoned airport to restore habitat for six species of birds that require an area rich in tall grasses. workers must continually remove trees that are begining to invade the area as a result of  a) direct harvesting b) genetic engineering c) evolutionary change d) ecological succession 14) Lichens are composed of two organisms, a fungus that cannot make it own food and algae that contains chlorophyl. Lichens may live on the bark of trees or even on bare rock. They secrete acids that tend to break up the rock that they live on helping to produce soil. As soil accumulates on the broken rock and dead lichens, other organisms such as plants begin to grow. The ability of lichens to alter their enviornment, enabling other organisms to grow and take their places in that environment is one step in the process of a) biological evolution b) ecological succession c) maintenance of cellular communication d) differentiation in complex organisms 15) A slab of bare rock is covered with lichens, in time moss covers the rock followed by grasses and finally by small shrubs and tree saplings. In this example the lichens represent a) a climax community b) dominant species c) secondary consumers d) pioneer organisms 16) Which statement best describes the pioneer organisms involved in ecological succession a) they do not require sunlight b) they are the last organisms to appear c) they modify the environement d) they are restricted to desert biomes 17) Which organisms would most likely be the pioneer organisms on a newly formed volcanic island a) conifers b) lichens c) deciduous trees d) tall grasses 18) Years after the lava from an erupting volcano destroyed an area, lichens started to grow in that area. These were gradually replaced by grasses, shrubs, conifers and deciduous forests. In this sequence of events the lichens functioned as  a) primary consumers b) climax organisms c) abiotic factors d) pioneer organisms 19) Which two groups of organisms are most likely to be pioneer organisms a) song birds and squirrels b) lichens and algae c) deer and black bears d) oak and hickory trees 20) Which organisms are most likely to occupy the bare rock habitat of a mountain top a) lichens b) legumes c) hemlock trees d) grasses 21) An established ecosystem may remain stable over a hundred years because a) species interdependence is absent b) there is a lack of variety in a species c) no competition exsists between the species d) they are natural checks on the species 22) What is a characteristic of a stable environment a) It usualy contains only one type of producer b) It usually contains a great diversity of species c) It contains simple food chains that have more consumers than producers d) It contains complex food webs that have more heterotrophs than autotrophs 23) Which statement concerning the climax stage of an ecological succession is correct a) It changes rapidly b) It persists until the environment changes c) It is the first the community to inhibit an area d) It consist entirely of plants 24) A pond ecosystem may be replaced by a terrestrial ecosystem over a period of time. The type of terrestrial that will be established depends on the  a) climatic limitations of the geographic area of the pond b) number of carnivors present within the geographic area of the pond c) Concentration of nitrogen dissolved in the pond water d) rate of photosynthesis in autotrophs growing in the pond water 25) The type of climax vegetation that becomes established in an area depends most upon the  a) rate of photosynthesis in autotrophs b) number of carnviores present c) climatic conditions present d) concentration of nitrogen in the air 26) Climax community is generally established most directly as a result of a a) catastrophic climatic change b) series of successive ecological stages c) long period of evolutionary change d) change in the dominant fauna 27) Scientist have studied the return of plant life on mount st. helens ever since the volcano erupted in 1980. Wildflowers began colonizing the area followed by shrubs and small trees. Scientists predict that it will likely take hundreds of years before the area returns to a forest dominated by fir and hemlock trees. These changes are an example of  a) humans degrading an ecosystem by removing wildflowers b) the loss of genetic varioation in a plant species c) the growth of a forest through ecological succession d) the biological evolution of wildflowers, shrubs and trees 28) What situation is most likely to lead to ecological succession a) the fish populations in a large lake remain the same for many years b) Hunters are allowed to hunt wolves, with no limits, for one season c) The industrialization increase in an area resulting of the increased burning of fossil fuels d) A farmer who has planted corn for many years retires and the field is left abandoned

nutrient cycles

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