Difference between revisions of "AY Honors/Ecology - Advanced/Answer Key"

Revision as of 13:26, 8 November 2007

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1. Have the Ecology Honor.

2. State the first and second laws of thermodynamics and explain how they are important to ecology.

First Law

”In any process, the total energy of the universe remains constant.”

More simply, the First Law states that energy cannot be created or destroyed; rather, the amount of energy lost in a steady state process cannot be greater than the amount of energy gained.

This is the statement of conservation of energy for a thermodynamic system. It refers to the two ways that a closed system transfers energy to and from its surroundings - by the process of heating (or cooling) and the process of mechanical work. The rate of gain or loss in the stored energy of a system is determined by the rates of these two processes. In open systems, the flow of matter is another energy transfer mechanism, and extra terms must be included in the expression of the first law.

In an ecological sense, the first law shows that a creature's energy must come from somewhere, and it must go somewhere as well. Primary producers transfer energy from the sun to primary consumers to secondary consumers at the top of the food chain. All along the way, some of the energy is dissipated in the form of heat.

Second Law

“The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.”

In a simple manner, the second law states that "energy systems have a tendency to increase their entropy" (heat transformation content) rather than decrease it.

A way of looking at the second law for non-scientists is to look at entropy as a measure of chaos. So, for example, a broken cup has less order and more chaos than an intact one. Likewise, solid crystals, the most organized form of matter, have very low entropy values; and gases, which are highly disorganized, have high entropy values.

To do:
Explain how this relates to ecology

3. Explain the three basic trophic (feeding) levels and give a good example of a plant or animal for each.

4. Explain or diagram the three types of ecological pyramids in the food web. Give an example of each layer of the pyramid.

5. Define the biogeochemical cycle, and explain or diagram all the basic components the cycle passes through.

6. Diagram or explain the basic steps in the flow of energy through the biotic environment (element) of an ecosystem. Begin with the sun.

7. Explain Liebig's Law of The Minimum and Shelford's Law of Tolerance, and state how these laws tell us how and why certain plants and animals become endangered or are eliminated when their habitat or community gets disturbed OR out of balance.

8. Choose a biological community in your area, such as a forest or woods; a swamp, lake or pond; pasture or meadow grassland; or a canyon or creek woods, etc., that is disturbed or ecologically out of balance in some way. Make a description of it, including how and to what extent it is disturbed. Then make recommendations as to how the community could be improved and, where possible, follow through and help to improve it in some way.

9. Spend a minimum of 20 hours doing active, productive work on an ecology project in your area. This may be done individually or as a group. Describe the project in general, but report specifically on your part in it.

10. Define the following terms:

a. Community

b. Raw materials

c. Photosynthesis

d. Chemosynthesis

e. Autotrophy

f. Heterotrophy

g. Ecological balance

h. Saprobe

i. Decomposer

j. Producer

k. Consumer

l. Limited factor

11. Find a Spirit of Prophecy quotation and a Bible text pertinent to ecology and explain their relevance and application to our day.

Adventist Youth Honors Answer Book/Ecology quotations

NOTE:These requirements may be expressed either verbally or in writing to a youth leader. An instructor is recommended but not required for this honor. Counsel with your youth leader or instructor before beginning requirements seven, eight and nine.

References

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-In [[ecology]] and [[Earth science]], a '''biogeochemical cycle''' is a circuit or pathway by which a [[chemical element]] or [[molecule]] moves through both biotic ("bio-") and abiotic ("geo-") compartments of an [[ecosystem]]. In effect, the element is recycled, although in some such cycles there may be places (called "sinks") where the element is accumulated or held for a long period of time.
+{{honor_header|3|1972|Nature|General Conference}}
+{{AY Master|Conservation}}
+==1. Have the Ecology Honor. ==
+{{ay_prerequisite|Nature|Ecology}}
+==2. State the first and second laws of thermodynamics and explain how they are important to ecology. ==
+===First Law===
+:'''''”In any process, the total energy of the universe remains constant.”'''''
-All chemical elements occurring in organisms are part of biogeochemical cycles. In addition to being a part of living organisms, these chemical elements also cycle through abiotic factors of ecosystems such as water ([[hydrosphere]]), land ([[lithosphere]]), and the air ([[atmosphere]]); the living factors of the planet can be referred to collectively as the biosphere. All the chemicals, nutrients, or elements — such as carbon, nitrogen, oxygen, phosphorus — used in ecosystems by living organisms operate on a '''closed system''', which refers to the fact that these chemicals are recycled instead of being lost and replenished constantly such as in an open system. The energy of an ecosystem occurs on an '''open system'''; the sun constantly gives the planet energy in the form of light while it is eventually used and lost in the form of heat throughout the [[trophic level]]s of a food web.
+More simply, the First Law states that energy cannot be created or destroyed; rather, the amount of energy lost in a steady state process cannot be greater than the amount of energy gained.
-The Earth does not constantly receive more chemicals as it receives light; it has only those from which it formed, and the only way to obtain more chemicals or nutrients is from occasional meteorites from outer space. Because chemicals operate on a closed system and cannot be lost and replenished like energy can, these chemicals must be recycled throughout all of Earth’s processes that use those chemicals or elements. These cycles include both the living biosphere, and the nonliving lithosphere, atmosphere, and hydrosphere. The term "biogeochemical" takes its prefixes from these cycles: Bio refers to the biosphere. Geo refers collectively to the lithosphere, atmosphere, and hydrosphere. Chemical, of course, refers to the chemicals that go through the cycle.
+This is the statement of conservation of energy for a thermodynamic system. It refers to the two ways that a closed system transfers energy to and from its surroundings - by the process of heating (or cooling) and the process of mechanical work. The rate of gain or loss in the stored energy of a system is determined by the rates of these two processes. In open systems, the flow of matter is another energy transfer mechanism, and extra terms must be included in the expression of the first law.
-The chemicals are sometimes held for long periods of time in one place. This place is called a '''reservoir''', which, for example, includes such things as [[coal]] deposits that are storing carbon for a long period of time. When chemicals are held for only short periods of time, they are being held in '''exchange pools'''. Generally, reservoirs are abiotic factors while exchange pools are biotic factors. Examples of exchange pools include plants and animals, which temporarily use carbon in their systems and release it back into the air or surrounding medium. Carbon is held for a relatively short time in plants and animals when compared to coal deposits. The amount of time that a chemical is held in one place is called its '''residence'''.
+In an ecological sense, the first law shows that a creature's energy must come from ''somewhere'', and it must ''go'' somewhere as well.  Primary producers transfer energy from the sun to primary consumers to secondary consumers at the top of the food chain.  All along the way, some of the energy is dissipated in the form of heat.
-The most well-known and important biogeochemical cycles, for example, include the [[carbon cycle]], the [[nitrogen cycle]], the [[oxygen cycle]], the [[phosphorus cycle]], and the [[water cycle]].
+===Second Law===
+:'''''“The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.”'''''
-Biogeochemical cycles always involve equilibrium states: a balance in the cycling of the element between compartments. However, overall balance may involve compartments distributed on a global scale.
+In a simple manner, the second law states that "energy systems have a tendency to increase their entropy" (heat transformation content) rather than decrease it.
-Biogeochemical cycles of particular interest in ecology are:
+A way of looking at the second law for non-scientists is to look at entropy as a measure of chaos. So, for example, a broken cup has less order and more chaos than an intact one. Likewise, solid crystals, the most organized form of matter, have very low entropy values; and gases, which are highly disorganized, have high entropy values.
-* [[nitrogen cycle]]
+{{TODO|Explain how this relates to ecology}}
-* [[oxygen cycle]]
-* [[carbon cycle]]
-* [[phosphorus cycle]]
-* [[sulfur cycle]]
-* [[water cycle]]
-* [[hydrogen cycle]]
-* [[nutrient cycle]]
-== Nitrogen cycle ==
+==3. Explain the three basic trophic (feeding) levels and give a good example of a plant or animal for each. ==
-[[Image:Nitrogen_Cycle.jpg|center|thumb|250px|right|Schematic representation of the flow of [[nitrogen]] through the environment.]]
+==4. Explain or diagram the three types of ecological pyramids in the food web. Give an example of each layer of the pyramid. ==
-{{main|Nitrogen cycle}}
+==5. Define the biogeochemical cycle, and explain or diagram all the basic components the cycle passes through. ==
-The [[nitrogen cycle]] is a much more complicated biogeochemical cycle but also cycles through living parts and nonliving parts including the water, land, and air. Nitrogen is a very important element in that it is part of both [[proteins]], present in the composition of the [[amino acids]] that make up proteins, as well as [[nucleic acids]] such as [[DNA]] and [[RNA]], present in nitrogenous bases. The largest reservoir of nitrogen is the [[Earth's atmosphere|atmosphere]], in which about 78% of nitrogen is contained as nitrogen gas (N<sub>2</sub>). Nitrogen gas is “fixed,” in a process called [[nitrogen fixation]]. Nitrogen fixation combines nitrogen with oxygen to create [[nitrates]] (NO<sub>3</sub>).
+==6. Diagram or explain the basic steps in the flow of energy through the biotic environment (element) of an ecosystem. Begin with the sun. ==
+==7. Explain Liebig's Law of The Minimum and Shelford's Law of Tolerance, and state how these laws tell us how and why certain plants and animals become endangered or are eliminated when their habitat or community gets disturbed OR out of balance. ==
+==8. Choose a biological community in your area, such as a forest or woods; a swamp, lake or pond; pasture or meadow grassland; or a canyon or creek woods, etc., that is disturbed or ecologically out of balance in some way. Make a description of it, including how and to what extent it is disturbed. Then make recommendations as to how the community could be improved and, where possible, follow through and help to improve it in some way. ==
+==9. Spend a minimum of 20 hours doing active, productive work on an ecology project in your area. This may be done individually or as a group. Describe the project in general, but report specifically on your part in it. ==
+==10. Define the following terms: ==
+===a. Community  ===
+===b. Raw materials  ===
+===c. Photosynthesis  ===
+===d. Chemosynthesis===
+===e. Autotrophy  ===
+===f. Heterotrophy ===
+===g. Ecological balance===
+===h. Saprobe===
+===i. Decomposer ===
+===j. Producer ===
+===k. Consumer===
+===l. Limited factor ===
+==11. Find a Spirit of Prophecy quotation and a Bible text pertinent to ecology and explain their relevance and application to our day. ==
+{{:Adventist Youth Honors Answer Book/Ecology quotations}}
-Nitrates can then be used by plants or animals (which eat plants or eat animals that have eaten plants). Nitrogen can be fixed either by lightning, industrial methods (such as for fertilizer), in free nitrogen-fixing bacteria in the soil, as well as in nitrogen-fixing bacteria present in roots of [[legumes]] (such as [[rhizobium]]). Nitrogen-fixing bacteria use certain enzymes that are capable of fixing nitrogen gas into nitrates and include free bacteria in soil, symbiotic bacteria in legumes, and also [[cyanobacteria]], or '''blue-green''' algae, in water.
+==NOTE:These requirements may be expressed either verbally or in writing to a youth leader. An instructor is recommended but not required for this honor. Counsel with your youth leader or instructor before beginning requirements seven, eight and nine. ==
+==References==
-After being used by plants and animals, nitrogen is then disposed of in decay and wastes. [[Detritivores]] and [[decomposers]] decompose the detritius from plants and animals, nitrogen is changed into [[ammonia]], or nitrogen with 3 hydrogen atoms (NH<sub>3</sub>). Ammonia is toxic and cannot be used by plants or animals, but nitrite bacteria present in the soil can take ammonia and turn it into [[nitrite]], nitrogen with two oxygen atoms (NO<sub>2</sub>). Although nitrite is also unusable by most plants and animals, nitrate bacteria changes nitrites back into nitrates, usable by plants and animals. Some nitrates are also converted back into nitrogen gas through the process of [[denitrification]], which is the opposite of nitrogen-fixing, also called nitrification. Certain denitrifying bacteria are NOT responsible for this.
+[[Category:Adventist Youth Honors Answer Book|{{SUBPAGENAME}}]]
-[[Category:Ecological cycles]]
-[[Category:Geochemistry]]
-[[Category:Biogeography]]
-[[br:Sikl biojeochimik]]
-[[da:Stofkredsløb]]
-[[es:Ciclo biogeoquímico]]
-[[fr:Cycle biogéochimique]]
-[[it:Ciclo biogeochimico]]
-[[nl:Biochemische kringloop]]
-[[sv:Biogeokemiskt kretslopp]]
-[[th:วัฏจักรทางชีวธรณีเคมี]]
-[[zh:生物地質化學循環]]